Vyborg-Petrozavodsk Offensive Operation

The 'Vyborg-Petrozavodsk Offensive Operation' was the Soviet overall designation of the strategic group of operations designed to force Finland out of the war (10 June/9 August 1944).

Undertaken by General Leonid A. Govorov’s Leningrad Front and General Kiril A. Meretskov’s Karelia Front on the Karelian isthmus and East Karelia fronts of the 'Jatkosota' continuation war, the undertaking comprised the 'Vyborg Offensive Operation' (10/20 June) by the Leningrad Front, the 'Virojoki-Lappeenranta Offensive Operation' (21 June/15 July) by the Leningrad Front, the 'Koivisto Landing Operation' (20/25 June) by the Baltic Fleet, the 'Svir-Petrozavodsk Offensive Operation' (21 June/9 August) by the Karelia Front, and the 'Tuloksa Landing Operation' (23/27 June) by the Ladoga Naval Flotilla.

As noted above, and otherwise known as the 'Karelian Offensive Operation', the 'Vyborg-Petrozavodsk Offensive Operation' was a strategic undertaking in which the Soviet forces captured East Karelia and Viipuri (Vyborg in Russian). After this, though, the fighting entered a stalemate phase.

In January 1944 Soviet forces had raised the German siege of Leningrad and drove Generalfeldmarschall Georg von Küchler’s (from 9 January Generalfeldmarschall Walter Model’s) Heeresgruppe 'Nord' back to the line linking Narva, Lake Ilmen and Pskov. Appreciating the strategic significance of its southern co-belligerent’s reversal of fortunes, Finland asked for peace conditions in February, but the Finnish parliament believed that the proposed Soviet terms impossible of compliance.

After Finland had rejected the proposed peace conditions and Germany had halted the Soviet advance, the Stavka began to develop an offensive to force Finland’s exit from the war. To achieve this object, the Stavka decided to undertake the 'Vyborg-Petrozavodsk Offensive Operation', which was planned on the basis of a two-pronged offensive, one from Leningrad via Vyborg to the Kymi river, and the other across the Svir river through Petrozavodsk and Sortavala past the 1940 border, followed by an advance deep into Finland. The plan called for the Finnish army to be destroyed on the Karelian isthmus, and the remnants of the Finnish forces to be pinned against the western shore of Lake Ladoga between the two assaults and Lake Saimaa.

The offensive’s primary strategic objectives were therefore to drive Sotamarsalkka Carl Gustaf Emil Mannerheim’s Finnish forces away from the area to the north of Leningrad, to drive Finland out of the war, and to create better conditions for a major offensive to the south against Germany.

The Finnish army had been preparing defensive fortifications since 1940, and three lines of defence on the Karelian isthmus, which came under the operational command of Kenraaliluutnantti Karl Lennart Oesch with elements of the II Armeijakunta, III Armeijakunta, IV Armeijakunta, V Armeijakunta and VI Armeijakunta (corps). The first two lines were the 'Pää-linja' (Main Line), which was constructed along the front line of 1941, and the 'Vammelsuu-Taipale-linja' ('VT Line') some 12.5 miles (20 km) behind the Main Line. These lines were reinforced with numerous concrete fortifications, but at the time of the Soviet offensive had not yet been completed. The third line was the 'Viipuri-Kuparsaari-Taipale-linja' ('VKT Line'), but this was still largely in the planning stage at the time of the Soviet offensive, though work on construction of some of the fortifications had begun late in May 1944 along the Viipuri sector of the line. On the northern bank of the Svir river, the Finnish army had prepared an area of defence in depth which was fortified with strongpoints based on concrete pillboxes, barbed wire entanglements, obstacles and trenches. After the 'Talvisota' winter war, the 'Salpa-linja' (Salpa Line) had been constructed behind the 1940 border with concrete bunkers in front of the Kymi river.

To overcome these obstacles, the Stavka assigned to the Leningrad Front 11 infantry divisions and nine tank and assault gun regiments: this meant that there were 19 divisions, two division-strength fortified regions, two tank brigades, 14 tank and assault gun regiments, and more than 220 artillery batteries (almost 3,000 guns and launchers) in the isthmus. Some 1,500 warplanes of General Polkovnik Stepan D. Rybalchenko’s 13th Air Army and the air arm of Admiral Vladimir F. Tributs’s Baltic Fleet, which also committed surface ships and naval infantry units.

To the east of Karelia, the Stavka planned to use nine divisions, two engineer brigades, two tank brigades and three assault gun regiments, raising the whole strength to 16 divisions, two fortified regions, five independent rifle brigades, two tank brigades, three assault gun regiments and three tank battalions. These were supported by the Lake Ladoga and Lake Onega Flotillas and General Leytenant Ivan M. Sokolov’s 7th Air Army.

On the Karelian isthmus front there were some 120 Soviet pieces of artillery per kilometre of front, with as many as 220 pieces of artillery per kilometre on the breakthrough sector at Valkeasaari. In addition to the heavy coastal artillery of the Leningrad area and the guns of the most potent ships of the Baltic Fleet (old battleship Oktyabrskaya Revolutsiya with 305-mm [12-in] guns, and heavy cruisers Kirov and Maxim Gorky with 180-mm [7.1-in] guns) Stavka had also assigned heavy siege artillery ranging in calibre from 280 to 305 mm (11 to 12 in) in support of the attack.

On 9 June, one day before the main Soviet offensive, most of the 13th Air Army’s 1,600 aircraft delivered a major aerial assault. At the same time, artillery units of the Leningrad Front and the Baltic Fleet shelled Finnish positions for 10 hours. The Finnish forces were in well-fortified positions, but the Soviet air attacks nonetheless surprised the defending Finns and undermined their will to resist, resulting in the retreat of many Finnish units and the desertions of many thousands of men.

On 10 June, General Polkovnik Dmitri N. Gusev’s 21st Army, spearheaded by the XXX Guards Corps, opened the offensive on the Valkeasaari sector, which was held by the 1st Jalkaväkirykmentti (infantry regiment) of Kenraalimajuri Juhani Sihvo’s Finnish 10th Divisioona (division). During the day, the Soviets captured a number of front-line trenches and destroyed fortifications, shattering the Finnish defence line along the breakthrough sector.

On 13 June, the Soviet 21st Army’s offensive reached the partially completed 'VT-linja' and had achieved a breakthrough in the area of Kuuterselkä by 15 June. Though the line was breached, the Finns' sturdy resistance managed to check further Soviet advances in this sector.

At the same time as the fighting at Kuuterselkä, General Major Aleksandr I. Cherepanov’s 23rd Army attempted to break through what had been perceived as a weak point in the 'VT-linja' at Siiranmäki, but here the Finns were able to make their first use of the Panzerfaust and Panzerschreck anti-tank weapons delivered by Germany. Although the Finnish troops thus managed to contain the Soviet breakthrough at Siiranmäki, this was not sufficient to ensure that the Finns kept the 'VT Linja' as this had already been breached at Kuuterselkä. The Soviet LXXXXVIII Corps, which was engaged in Siiranmäki with the Finnish 7th Jalkaväkirykmentti, reported that between 13 and 16 June it had lost 3,784 men including 887 killed. Soviet (and especially Guards) formations and units suffered heavy losses in the Siiranmäki and Kuuterselkä areas with 20,000 men killed, wounded and missing.

The Finns tried to buy time through the use of delaying actions during their retreat so that additional forces from eastern Karelia could reach the front, and so that the 'VKT-linja' could be prepared for combat. However, on 19 June formations of the Leningrad Front had reached Viipuri, and the first phase of the Soviet offensive was completed by the capture of the city on 20 June after Eversti Armas Kemppi’s (from 22 June Eversti Yrjö Sora’s) defending 20th Prikaati (brigade) fled in panic. Although the Leningrad Front had managed to capture Viipuri within the time frame ordained by the Stavka, it had not been able to prevent retreating Finnish units from regrouping and fortifying on the 'VKT-linja'. Unlike many of the battles on the Karelian isthmus, in this undertaking the Soviets had been unable to trap any large Finnish formations above company level, and the Finns had therefore managed to retreat in comparatively good order. At the same time increasing numbers of Finnish reserves were reaching the 'VKT-linja', where terrain was considerably more favourable for infantry defence than for armoured attack. The Soviet 21st Army was also starting to suffer greatly from logistical problems after its rapid 70-mile (120-km) advance to the west.

By this time Mannerheim had asked for German assistance, and on 17 June aircraft of the Luftwaffe’s Gefechtsverband 'Kuhlmey', under the command of Oberstleutnant Kurt Kuhlmey, arrived in Finland, followed on 21 June by Hauptmann Hans Wilhelm Cardeneo’s 303rd Sturmgeschützabteilung (at half strength) and Generalmajor Hero Breusing’s 122nd Division. Additionally, the new German Panzerfaust and Panzerschreck anti-tank weapons were issued to Finnish troops. Late on 21 June, Joachim Ribbentrop, the German foreign minister, arrived to Finland seeking to extract political concessions in return for the German military help.

On 21 June, the Stavka ordered continued attacks toward the Imatra-Lappeenranta-Virojoki defence line, on the 'Salpa-linja' sector of the front. Another group was to attack to the north in the direction of Käkisalmi and surround the Finns defending the eastern part of the 'VKT-linja', and preparations were to be made for an advance towards Kotka, Kouvola and the Kymi river.

On the same day, the Finnish government asked the USSR for peace terms. The response arrived during the following day and demanded that the Finns capitulate before any conditions could be presented. This created confusion in the Finnish government, among whom Risto Ryti and Väinö Tanner, the president and minister of finance respectively, were willing to repeat the inquiry about conditions, while others opposed even the thought of any capitulation. During the meeting Mannerheim was called, and he stated that the Soviet demand constituted an unconditional surrender. When the negotiation trip to Moscow, which the statesman Juho Kusti Paasikivi made in March and April 1944 at the instigation of the Soviet ambassador in Stockholm, but then emerged as a Soviet dictation of terms, was remembered, the government decided to interpret the Soviet response as a demand for unconditional surrender. It seemed that after Finnish unwillingness to accept the Soviet proposals in April 1944, on the grounds of the excessive Soviet demands for reparation, Finland was to be offered only unconditional surrender. This was in accord with the statement of the British prime minister, Winston Churchill, that as an Axis co-belligerent, Finland must surrender unconditionally, an interpretation which the Soviets denied. Moreover, it is also known that on 26 June Iosif Stalin told the US ambassador, Averell Harriman that American diplomats could try to clarify to the Finns that he did not intend to take over the country.

With reinforcements, the Finnish army had 268,000 men, 2,350 pieces of artillery, 110 tanks and assault guns, and 250 aircraft facing the two Soviet fronts. Some 40% of the Finnish men and guns, together with all the armour, were on the Karelian isthmus. In total, the Soviets had a 1.7/1 superiority in men, 5.2/1 superiority in guns, and 6.7/1 superiority in warplanes and tanks. However, with 14 infantry divisions (each of 12,000 men), one armoured division (of 9,200 men), five infantry brigades (each of 5,100 men), one cavalry regiment (of 4,300 men), seven independent border-defence jäger battalions, coast-defence forces and both headquarters and corps artillery units, the Finns could deploy less than 230,000 men. Fewer than 40 Finnish tanks and assault guns were modern machines such as German StuG III assault guns and captured Soviet T-34 and KV-1 tanks, and fewer than 100 modern warplanes in the form of Messerschmitt Bf 109 day fighters and Junkers Ju 88 medium bombers were available. The Soviet matériel advantage was about 20/1 in the middle of June.

The offensive continued on 25 June, when Soviet forces breached the 'VKT-linja' at Tali, between Viipuri Bay and the Vuoksi river. On 26 June Ryti gave a guarantee to Ribbentrop that Finland would fight to the end alongside Germany.

When it became evident that a Soviet breakthrough was not possible at Ihantala, the Leningrad Front now sought to effect a double envelopment of the Finnish defence with twin assaults at Viipuri Bay and Vuosalmi. However, the Finns were able to hold their positions in these sectors. On 12 July the Stavka ordered the Leningrad Front to release offensive elements, and on 15 July the Soviet troops were ordered to assume a defensive posture as offensive elements (mostly armour) were transferred to the south for use in 'Bagration'.

How much of the Soviet offensive capability was actually redeployed from the Karelian isthmus to other fronts is moot. Captured reports of the strength of the Soviet regiments and battalions, especially in the Ihantala and Äyräpää areas, suggested heavy losses, and it has been estimated that 10 divisions each had on strength fewer than 2,000 men, a fact with suggests that these formations all had very small numbers of men at battalion level. The Soviet losses had been heavy, especially among guard divisions.

The Soviets tried to penetrate deeply to the west after the Battle of Ihantala: in the Äyräpää area this effort lasted to 18 July, and in the Karelian Front’s area to a time early in August. These offensive efforts were maintained until it was appreciated that there was no possibility of achieving any decisive breakthrough. After the seizure of Viipuri, the Soviet plan had been to take the Kymi river area and continue a campaign of attrition against the Finnish forces when their forces in Karelia had been trapped.

Once the Soviet offensive on the Karelian isthmus had pushed to the north past Koivisto, the Finnish forces defending the islands became isolated. After its 21st Army had failed to take the islands, the Leningrad Front ordered the Baltic Fleet to capture them. The initial Soviet landing was contained, but the small Finnish navy soon evacuated the defending forces in a movement which was in general unopposed. Although the eagerness of their commanders to evacuate preserved the defending forces, the loss of the islands proved costly because the Baltic Fleet was provided with a safe route into Viipuri Bay.

After losing Viipuri, the Finns concentrated their defence in the Tienhaara region, which seemed favourable for defensive purposes as local waterways cut the already narrow battlefield into several islands.

By 20 June, the Soviet forces were already literally at the gates of Viipuri, and while the 20th Prikaati had been transferred from the reserve of Oesch’s Ryhmä 'Aunas' (Aunas Group) in eastern Karelia to defend the city, it had been inadequately supplied and lacked effective anti-tank weapons as it lacked 75-mm (2.95-in) PaK 40 anti-tank guns and both knowledge and experience of the use of the few Panzerfaust and Panzerschreck anti-tank weapons available to it. The 20th Prikaati was therefore effectively incapable of resisting any Soviet armoured assault. This took place on 22 June as the Battle of Tienhaara as Soviet forces of the CVIII Corps' 90th Division, supported by the 260th independent Heavy Breakthrough Tank Regiment and 1,238th Assault Gun Regiment swept forward. The 20th Brigade's resistance failed swiftly with many of its men fleeing either in panic or in response to supposed orders to withdraw.

Majuri Alpo Marttinen’s 61st Jalkaväkirykmentti, whose men were largely of ethnic Swedish origin and volunteers from Sweden, was part of Kenraalimajuri Alonzo Sundman’s 17th Divisioona and arrived in the Karelian isthmus from Svir immediately after the loss of Viipuri, and on 22 June was deployed for the defence of Tienhaara on the coastal road leading to the north from Viipuri toward inner Finland on the shore of the Kivisillansalmi strait. Here the regiment relieved battle-worn units. Aided by potent artillery support and the local air superiority of the Gefechtsverband 'Kuhlmey', the regiment was able to hold the Tienhaara region, including the Kivisillansalmistrait, as it checked repeated attacks by the 90th and 372nd Divisions of the CVIII Corps, supported by strong artillery fire, to take a location suitable for the breaching of the 'VKT-linja'.

Govorov now decided that further attempts to cross the local waterways would be too costly and time-consuming, and instead concentrated the bulk of his forces in the Juustila and Ihantala area and thus making a contribution to the events which led to fighting in the Tali-Ihantala region. Finnish forces held Tienhaara until the ceasefire which ended the 'Jatkosota'.

On 15 June, the Soviet breakthrough of the Finnish defence lines at Valkeasaari and Kuuterselkä compelled the Finnish forces on the Karelian isthmus to withdraw to the still incomplete Finnish 'VKT-linja'. Although the Soviet advance took Viipuri on 20 June, the main offensive was halted by the stubborn Finnish defence of the Tali-Ihantala region. Despite heavy fighting and use of fresh reserves, the 'VKT-linja' bent but did not break, forcing the Leningrad Front to seek alternate routes past the Finnish defences. The Leningrad Front followed roughly the same plan as in the 'Talvisota' winter war and thus to a crossing of Viipuri Bay.

In the Battle of Viipuri Bay between 30 June and 10 July, the Soviet forces involved in the battle were part of Govorov’s Leningrad Front, which assigned the task to General Leytenant Ivan T. Korovnikov’s 59th Army in the form of the XLIII Corps. The infantry formations involved in the offensive were the 124th and 224th Divisions with the 80th Division in reserve, and only a few Soviet tanks were assigned to provide support, which also included several artillery regiments together with air support, light naval vessels and the 20th Naval Infantry Regiment of the Baltic Fleet.

Initially the Finnish forces responsible for the defence of the area were the 22nd Rannikkotykistörykmentti (coastal artillery regiment) of Eversti Pekka Enkainen’s [e/]Itäisen Suomenlahden Rannikkoprikaati (Eastern Bay of Finland Coastal Brigade) under the control of the Finnish navy’s commander, and parts of Tähtinen’s Ratsuväkiprikaati under the Finnish V Armeijakunta. Both the 22nd Rannikkotykistörykmentti and Breusing’s newly arrived 122nd Divisioona were subsequently subordinated to the V Armeijakunta. A large part of the Finnish navy supported the defensive operations.

Initially the islands in Viipuri Bay were in a fairly strong position with the Finnish garrison on the Koivisto islands preventing Soviet naval forces from gaining access to the bay. The Baltic Fleet did manage to land a small assault force on the islands, but the Finnish garrison contained this small beach-head. Nevertheless, Finnish headquarters decided it would be impossible to keep the troops in the islands supplied in the face of Soviet air supremacy, and an unopposed evacuation of the islands was made, and this opened the route for the Baltic Fleet enter the bay safely.

The fighting in Viipuri Bay started on 30 June as the 224th Division tried to take Teikari and Melansaari islands. Finnish forces on the islands drove the attacks back, inflicting heavy losses on the Soviet troops in the process. Renewed Soviet attacks on 4 July met success in the islands close to Uuras, but the Soviet attempt to make a landing on Teikari island was again repulsed with heavy losses.

On 4 and 5 July, the Finnish navy, supported by several German Marinefährprahm gun barges, made several raids on targets in Viipuri Bay as part of an attempt to disrupt the Soviet landings on the islands. Heavy Soviet resistance from shore-based artillery, numerous motor torpedo boats and warplanes compelled the Finns to withdraw even before they reached their target area. Although none of the Finnish ships was sunk, most of them suffered crew casualties and were badly damaged, requiring immediate repairs. This situation effectively forced the Finnish naval forces to withdraw from the battle. Of the Finnish ships, the worst damage was suffered by the auxiliary gunboat Viena during a Soviet air attack on its anchorage. The ship came close to sinking but was still able to return to Helsinki for repairs.

Parts of the 124th Division captured the islands of Teikari and Melansaari on 5/6 July. Fighting on other islands closer to the northern shore continued until 8 July, when the 124th and 224th Divisions attempted landings on the northern shore of the bay only to be repulsed by the 122nd Division. The 59th Army switched to a defensive posture after these attempts, and fighting in the bay came gradually to a close.

In costly battles, the 124th and 224th Divisions of the 59th Army’s XLIII Corps had managed to capture the islands dominating Viipuri Bay, but failed to gain a beach-head on the bay’s northern shore. With both the initial attempt at Tali-Ihantala and the crossing at Viipuri Bay blocked, the Leningrad Front turned its attention to the still undecided battles raging in the region of Äyräpää and Vuosalmi.

Also known as the Battle of Äyräpää-Vuosalmi, the Battle of Vuosalmi was fought between 4 and 17 July. After they had conceded defeat in the Battle of Tali-Ihantala, the Soviets tried to break the Finnish positions at Vuosalmi and encircle the southern part of the Finnish forces in the Karelian isthmus. Here the 23rd Army had made unsuccessful small-scale attacks on the Finnish defences of the Äyräpää region for nearly two weeks, and this army’s lack of success led to a change of command on July 3, when General Leytenant Vasili I. Shvetsov arrived from the 21st Army, of which he had been deputy commander.

The Finnish defences in the Vuosalmi area at first comprised only Kenraalimajuri Ilmari Martola’s and then from 7 July Kenraalimajuri Arne Blick’s 2nd Divisioona, though this was later reinforced by Kenraalimajuri Ernst Lagus’s Panssaridivisioona (armoured division) as the battles in the Tali-Ihantala region started to slow.

It was the Leningrad Front’s 23rd Army which was allocated the task of making a crossing over the Vuoksi river and a breakthrough at Vuosalmi on the river’s northern bank. For this task 23rd Army assigned first General Leytenant Georgi I. Anisimov’s LXXXXVIII Corps (92nd, 281st and 381st Divisions) and later General Major Sergei B. Kozachek’s CXV Corps (10th, 92nd and 142nd Divisions).

The Finnish positions were very unfavourably located on the Äyräpää ridge with the wide Vuoksi river behind them. Though the position was very unfavourable, the Äyräpää ridge dominated the lower terrain of the river’s northern bank. The LXXXXVIII Corps began to deliver powerful attacks on 4 July and severe fighting for control of the ridge lasted to 9 July, when the Finns withdrew to the river’s northern bank. The CXV Corps then continued the attack, crossed the river on 9 July, reinforced its bridgehead and had all three of its divisions in the bridgehead by 11 July. The Finnish forces were also reinforced by the depleted Armoured Division arriving directly from Ihantala, and on 11 July both sides simultaneously attempted to attack before halting when they ran into attacking enemy formations. Although the Soviets now had access to the flatter terrain on the river’s northern side, which offered advantages for the deployment of armour, the Finns were able to prevent any further Soviet advance. The following Finnish counterattacks in the Vuosalmi area also won no gains, so both sides went onto the defence in the middle of July.

Of the 30,000 men, 35 assault guns and 200 pieces of artillery they deployed, the Finns lost 795 men killed, 4,976 wounded and 354 missing, as well as two assault guns destroyed. The Finnish artillery fired more than 122,000 shells in Äyräpää and Vuosalmi from 20 June to 17 July. Of the 60,000 men, 150 tanks and 300 pieces of artillery they deployed, the Soviets lost 3,050 men killed,11,750 wounded and 250 missing, as well as 60 tanks.

Govorov, the commander of the Leningrad Front, strongly criticised the commanders of the 23rd Army, LXXXXVIII Corps and CXV Corps after the offensive in the Vuosalmi area failed to yield any concrete results despite the expenditure of many men and much equipment.

Farther to the north, the Karelian Front had attacked in the Olonets sector of White Karelia on 20 June. The Finnish forces in this area were weak, and could not stop the Soviet offensive, which reached Olonets on 25 June and on 29 June took Petrozavodsk, one of the operation’s primary objectives. The long advance and the delaying tactics of the Finnish forces sapped the Soviet strength, however, and the main push of the 7th Army stopped at the Finnish 'U-linja'. the 7th and 32nd Armies attempted to bypass the 'U-linja' by attacking farther to the north but failed to break through in battles fought in the wilderness of Karelia. The last attempt to resume the offensive was made still farther to the north by two of the 32nd Army’s divisions, but these were defeated by Finnish counterattacks in the Battle of Ilomantsi.

On the Svir river area of the front, the Finns had previously withdrawn most of its forces from the river’s southern bank, so when the Soviet offensive started on 21 June, it did not achieve the desired surprise. The Karelian Front’s 7th Army (with the XXXVII Guards, IV and LXXXXIX Corps) crossed the river using amphibious vehicles on the following day and secured a bridgehead 5 miles (8 km) deep and 10 miles (16 km) wide. After securing the crossing, the Soviet forces continued to pursue the Finnish withdrawal toward the defences of the 'PSS-linja'.

On 23 June, the 70th Naval Infantry Brigade attacked and captured a bridgehead behind the Finnish lines and also beyond the 'PSS-linja' in the area between the Viteleenjoki and Tuuloksenjoki rivers, cutting the main road and railway connections along the western shore of Lake Ladoga. As the Finns had previously moved most of their coastal defences to the Karelian isthmus, the Soviet landing met only a skeletal defence. Finnish attempts to drive the Soviets back into Lake Ladoga proved unsuccessful, but pushed Soviets into the difficult situation as their ammunition and supplies started to run short. The situation in the Soviet beach-head was improved when the 3rd Naval Infantry Brigade started its own landings during the evening of 24 June. Bad weather then hampered the Soviet effort, but the brigade was finally unloaded on 26 June and able to link with the advancing 7th Army.

These landings caused the Finns some considerable trouble as they severed the railway line running along the shore of lake Ladoga. The cutting of the road at the same time was of lesser consequence as Finns had already built new parallel roads farther inland as they had perceived the threat inherent in a successful Soviet landing. The heavy traffic of the withdrawing forces totally ruined the new road, however, and this made inevitable the abandonment of some equipment. Although the Finns managed to withdraw to the new defensive line, on 28 June the advancing Soviets broke through the new line at Vitele, and this forced the Finns to continue delaying the Soviets while at the same time withdrawing toward the 'U-linja'. For the Soviets, the 'Svir-Petrozavodsk Offensive Operation' cost at least 45,000 men, and the Finns about 11,000 men. The Soviets estimated that they had captured 933 pieces of Finnish artillery and 18,000 rounds of ammunition, though many of the guns had been rendered inoperable.

Fought between 15 and 17 July, the Battle of Nietjärvi was a Finnish victory. Nietjärvi is a village by the Nietjärvi lake in the Ladoga Karelia district to the north of Lake Ladoga in the south-western corner of the Aunus Karelia frontier region. On 11/12 July, Kenraaliluutnantti Paava Talvela’s Ryhmä 'Aunas' (Aunas Group) was awaiting the Soviet offensive against the 'U-linja', whose construction had been launched seven months earlier, along the line linking Nietjärvi, Lemetti and Loimola, as the defence line behind the 'PSS-linja', itself the most heavily fortified defence line in Olonets Karelia to the north and north-east of Lake Ladoga.

Up to July 1944, the front line had closely followed the banks of the Svir river, which flows from Lake Onega to Lake Ladoga. Before battle had begun, the Finns had abandoned their bridgehead on the southern bank of the Svir river when troop transfers to the Karelian isthmus made it impractical to retain. Behind the front line there was a secondary defence line in front of the 'PSS-linja': the Finns intended this as a means to slow any Soviet advance.

The long-awaited Soviet offensive began with overwhelming force and managed to push through Finnish defences before stalling along the 'PSS-linja', but the Soviet combination of land advance and naval amphibious assault behind the Finnish lines rendered impossible the Finnish hope of holding the 'PSS-linja', and the Finns started to fall back toward the 'U-linja' even as they sought to delay the Soviet advance.

During the previous three weeks, the Finns had managed to delay the Soviet advance by blunting the forward edge of the Soviet attack. As they withdrew, the Finns halted in the 'U-linja', and after running into the Finnish defences the Soviets started to make local probing attacks against the 'U-linja' in order to find possible weak spots suitable for a breakthrough. These probes decided the Soviets to breach the Finnish defences along the main shore road at Nietjärvi and then to advance on Kittilä, whose seizure would provide access to the better maintained Finnish road network as well as several roads into the Finnish rear areas at Sortavala, Värtsilä and Matkaselkä.

At the break of day on 15 July, Kenraalimajuri Kustaa Tapola’s 5th Divisioona was deployed with Everstiluutnantti Ilmari Rytkönen’s 44th Jalkaväkirykmentti on the line between Lake Ladoga and Nietjärvi, and Everstiluutnantti Haikki Saure’s 2nd Jalkaväkirykmentti to the north-east of Nietjärvi.

On the morning of 15 July, the Soviet artillery and mortar units opened with a fierce fire preparation, and the clouds of dust, sand and smoke that resulted severely reduced the visibility, making it difficult to see anything. The Soviets followed the artillery preparation with a massed infantry assault supported by armour. By the middle of the day, the Finnish defence had managed to halt the Soviet attacks in every area but on the western side of Nietjärvi, where the 1/44th Jalkaväkirykmentti and 2/44th Jalkaväkirykmentti found it impossible to hold back the Soviets, who followed their initial success with another breakthrough attempt on the north-western shore of the Nietjärvi lake, at Yrjölä. Lack of reserves made it difficult for the Finns to respond, but by the evening the Finns had succeeded in halt all of the Soviet breakthrough attempt apart from a section, 440 yards (400 m) wide, which the Soviets still held. Throughout the evening the Soviet offensive continued relentlessly with the backing of strong air support. The Finnish air arm took part in the battle by bombing the Soviet forces on the south-eastern edge of the Nietjärvi lake.

The Finnish counterattack to regain the lost part of their defence line began in the morning. There was heavy fighting throughout the day. By the evening the Soviets still held part of the village of Nietjärvi and part of the defence line (in the form of a section comprising connected trenches on a low hill. As frontal assault was deemed to be too expensive, the Finns opted to isolate the Soviet units by assaulting along the trenches with artillery fire preventing any Soviet reinforcements from reaching the area. At 22.30, the Finnish guns and mortars began an artillery preparation which was immediately followed by an infantry assault along the trenches from each end using automatic rifles, hand grenades and flamethrowers.

In the early morning of 17 July, the Finnish units advancing along the trench line from each end managed to link with the help of flamethrowers. Only a small number of Soviet troops trapped in and round the trench line managed to escape. The Soviets attempted to support the troops fighting in the trench line, but the Finnish artillery prevented reinforcements from reaching the area.

Thus the Soviets had been unable to penetrate the defence of the 5th Divisioona in the 'U-linja'. The heaviest losses were suffered by the 114th Division, and the 762nd Regiment was totally destroyed. Most of the 114th Division’s two other regiments were also destroyed as well. Moreover, the 272nd Division suffered heavy losses. Of the Soviets' 80 tanks, some 40 which had attacked in the direction of Nietjärvi were also lost. The breakthrough attempt had cost the Soviets more than 6,000 casualties (2,200 men killed or missing and 4,000 wounded) out of the 15,000 men who had been committed. The Finns captured only a few Soviet soldiers.

Of the 5,000 men committed, the Finns lost about 500 dead or missing and 700 wounded.

The efficient co-operation of the Finns' forces helped the Ryhmä 'Aunas' to stop the Karelian Front’s advance along the shores of Lake Ladoga at the 'U-linja'. The excellent concentration of the Finnish field guns and mortars once again played a vital role, as it did in many other critical combats during summer of 1944.

The 7th Army’s attempt to outflank the 'U-linja' also led to a number of smaller engagements in the frontier area to the north of Lake Ladoga. The Soviet move to extend the front required the Finns to extend their line, and this paved the way for the battle of Ilomantsi fought farther to the north. The Finnish defence had prevented the Soviet forces from advancing from the northern side of Lake Ladoga into the battle of the Karelian isthmus. Had the Soviets not been stopped here, the Finnish forces fighting on the Karelian isthmus would have been trapped between two Soviet armies on the narrow isthmus in the area limited by the Gulf of Finland in the south and Lake Ladoga in the north.

The Battle of Ilomantsi was fought from 26 July to 13 August in an area approximately 25 miles (40 km) wide and 18.5 miles (30 km) deep close to the small town of Ilomantsi in the northern part of Karelia. The Finnish forces in the area before the battle comprised only Eversti Torvald Ekman’s 21st Prikaati later reinforced by Eversti Urho Tähtinen’s Ratsuväkiprikaati (cavalry brigade) and three smaller units in the form of the 3rd Rajajääkäripataljoona (border Jäger battalion) and the two battalions of the Osasto Partinen detachment. All the Finnish forces were subordinated to a temporary formation, the Ryhmä 'Raappana' (Raappana group) commanded by Kenraalimajuri Erkki Raappana and tasked with checking the Soviet advance and retaking the crossroads at the village of Kuolismaa.

As noted above, during the initial Soviet push the sole Finnish unit in its path was the 21st Prikaati of about 7,000 men, but as the front in the Karelian isthmus began to be stabilised the Ratsuväkiprikaati was rushed to Ilomantsi to reinforce the 21st Prikaati, bringing the Finnish strength on 31 July, when the counterattack began, to about 13,000 men.

On the other side of the front line, the forces of Meretskov’s Karelian Front driving toward Ilomantsi comprised two divisions of General Major Filip D. Garelenko’s 32nd Army, namely Polkovnik Vasili I. Zolotarzhov’s 176th Division and General Major Nikolai A. Chermukha’s 289th Division. As the battle lengthened and the advancing divisions were encircled, the Soviet forces in the area were reinforced by the 3rd, 69th and 70th Naval Infantry Brigades and other units. Soviet archives indicate that at the start of the Karelian Front’s offensive on 21 June, the two divisions had a combined strength of some 16,000 men, and that by 31 June and the beginning of the Finnish counterattack at Ilomantsi, this total had fallen to 11,000 men. After the 3rd Naval Infantry Brigade and the 69th and 70th Naval Rifle Brigades were arrived to support the encircled 176th and 289th Divisions, the combined Soviet infantry strength at Ilomantsi was slightly more than 20,000 men.

The Soviet offensive seemed initially to be a success as on 21 July the two assault divisions had reached the Finno-Soviet border of 1940 for only the first time during the entire Soviet offensive of 1944. Finnish reinforcements arrived on 28 July, and on 31 July Raappana launched his counterattack. By 1 August the Finns had cut the sole road nourishing the 176th Division, and by 3 August both divisions had been encircled as the Finnish forces used their motti envelopment tactics. Men of the Erillinen Pataljoona 4 disrupted the supply lines of the Soviet artillery, preventing it from delivering effective fire support.

The Soviets deployed three brigades with armoured support in an effort to reopen the road links to their encircled divisions, but the Finns prevented them. Renewed attacks distracted the Finns enough to allow the encircled Soviet forces to escape through the dense forest by abandoning their heavy equipment. Given the element of surprise and as a result of the Soviets' superior numbers, the Finnish troops encircling the divisions had little hope of containing organised break-outs, especially in the forests, so many of the encircled Soviets managed to escape to their own side, the last of them on 10 August.

The Utrio area played a central role in Raappana’s defensive plan. Fast-moving battalions of the Ratsuväkiprikaati, experienced in forest warfare, drove through this area between lakes, as a wedge between the 176th and 289th Divisions. The opening battles fell on the Finns' 6th Jägerpataljoona (battalion). When it encircled the Soviets at Leminaho and the Lutikkavaara hill, the Uudenmaa Ratsuväkirykmentti attacked through Utrio and the Ruukinpohja river, with flanking support by the 1st Jägerpataljoona.

In summary, two Soviet divisions were effectively decimated in this last major engagement on the Finnish front before the armistice was concluded early in September. The Finns had lost some 400 men killed and 1,300 wounded between 24 July and 13 August, and the Soviets 3,200 men killed, 3,450 wounded and 1,400 missing. The Soviets also lost more than 100 pieces of artillery, about 100 mortars and almost all of their other weapons and equipment in what had been the Finns' ninth tactical defence victory in a period of only a few weeks following the launch of the main Soviet offensive.

Over a period of 10 days, Raappana’s forces had fired more than 36,000 artillery shells, but in response the Soviet artillery in the Battle of Ilomantsi had been able to fire only 10,000 shells. The primary reason for the poorer Soviet artillery performance was the success of the Finnish tactics in disrupting the Soviet logistics.

The Finns had achieved notable victory in which is considered to have been the largest battle in the history of the Nordic countries, and the remnants of the two Soviet divisions had barely escaped destruction by breaking out from the encirclements. After the battle, the Stavka brought its offensive to a halt and effectively abandoned the Soviet demand for Finland’s unconditional surrender.

The Soviet 23rd Army joined the offensive by attempting to break through the Finnish lines between Tali and the Vuoksi river toward Noskua, but their several attacks were halted by the highly efficient Finnish artillery. Ultimately, the battle of Tali-Ihantala was a defensive strategic victory for the Finns as it blocked the possibility of the Soviet forces breaking through to the Finnish heartland and the road to Helsinki. Soviet military losses peaked on 28 June when the Leningrad Front reported the single-day loss of more than 5,000 men including 1,800 killed in action, which represented a 25% increase over the loss on 14 June when the Soviets reported the loss of almost 4,000 men including nearly 700 killed in action. The Finnish artillery caused a high proportion of these losses, its 250 pieces of artillery delivering 2,000 shells per minute into one small target area. Soviet units saw no chance of penetrating through this fire power. Moreover, the terrain favoured the defence and forced Soviet armoured units into what became narrow death traps. Finnish radio intelligence intercepted much of the Soviet radio traffic, providing the data for effective artillery and air counterattacks.

By the time of its end on 9 August, the 'Vyborg-Petrozavodsk Offensive Operation' had suffered a large number of tactical defeats at the hands of the Finnish forces but had nonetheless succeeded in reclaiming the eastern part of Karelia and driving the Finnish army to the northern side of Viipuri Bay Bay and the Vuoksi river. It also reopened the original route of the Soviet railway line to Murmansk and the White Sea Canal to the forces of the Karelian Front. However, the offensive failed to breach the 'VKT Linja' and reach the Kymi river as had been ordered by the Stavka. By the end of 1944’s summer, the Finnish forces were stronger and better equipped than ever before. Despite the losses it had suffered, the Finnish army managed to avoid any encirclement of battalion-sized units, and had and benefited from supplies delivered by Germany.

Soviet documents revealed after 1991, in what is now Russia once again, that the most important point of the plan (the destruction of the Finnish forces in the Karelian isthmus in a a fixed time and reaching the Kotka line) had failed. Despite this, the morale effect of the offensive on the Finnish leadership should not be underestimated. Even though the Finns had stopped the offensive in the Karelian isthmus after it had advanced about 60 miles (100 km), and the Battle of Ilomantsi had shown that the Finnish army was still a highly effective fighting force, it was estimated that had the Soviet offensive continued at its full strength, the Finnish army would have been able to endure for only an other three months at the most.

During the height of the offensive in June 1944, the Finns asked for negotiations and the Soviets responded with a demand for surrender, which in Finland was interpreted as an ambiguous demand for unconditional surrender and rejected. After the fighting had reached a stalemate in August 1944, another attempt to seek peace was made by Finland. In September 1944 the Soviets offered peace terms not significantly different from of April 1944, though some of the demands, which had been seen by the Finns as impossible too harsh, were reduced. Moreover, the Soviet war reparations demand was halved and the time to pay it had been lengthened. This was probably in part brought about by international pressure exerted on the Soviets, especially by the USA and UK. However, after the ceasefire the Soviets demanded that payments be based on 1938 prices which virtually doubled the actual amount to be paid, so the Finns were able to complain that the Soviets had only pretended to lower the reparations.

Despite the fact that not all of the goals set by the Stavka had been attained, the offensive forced Finland from the war and compelled it to accept Soviet peace terms, or at least was an important factor leading to the ceasefire negotiations which were resumed a month after the offensive had ended.