'Abstention' was a British attack on Kastelorizo in the Italian-held Dodecanese islands group (24/28 February 1941).

The undertaking was part of the British desire to destabilise the Italian position in this island group of the south-eastern part of the Aegean Sea, and the background to the operation can be found in the period when the British finally appreciated the fact that Malta, if it were held, could play an extremely important part in Mediterranean naval operations. This demanded a major strengthening of the island’s defences, especially against air attack, and this could be achieved only by the combination of fighters and anti-aircraft guns. An attempt in June 1940 to deliver Hawker Hurricane single-engined fighters across France to Malta and Egypt had not proved wholly successful, and the fall of France then rendered this route impossible and thus demanded the creation of an alternative route.

On 12 July the Admiralty informed Admiral Sir Andrew Cunningham, commanding the Mediterranean Fleet, that 24 Hurricane fighters (12 each for Malta and the Middle East) were about to be delivered by merchant vessel to Gibraltar, and asked for local advice on the practicality of forwarding the ship to Malta. Both Cunningham and Vice Admiral Sir James Somerville, commanding the Gibraltar-based Force 'H', thought that this would be to invite disaster, and Somerville proposed that the aircraft should be transferred to an aircraft carrier and flown off from a position to the south of Sardinia, with men and stores for the aircraft transported in two submarines. The elderly aircraft carrier Argus left the UK on 24 July with 12 Hurricane fighters to be flown to Malta in 'Hurry' (i).

Postponement of the date of Argus's departure from Gibraltar to 31 July required Cunningham to alter his plan for a diversion. Nevertheless he was able to arrange for a sweep by cruisers and destroyers into the Aegean Sea, this effort including a westward feint through the Kythira Strait, between the western end of Crete and Kythira island to the south of the Peloponnese, during the evening of 1 August. Two battleships and the fleet carrier Eagle would steam to the west into a position between Crete and Libya during daylight on 1 August, Cunningham thus hoping to generate the impression of a movement into the central Mediterranean which would deter the Italian surface forces in Sicily and southern Italy from moving to the west. The force sailed during the early hours of 27 July to cover an Aegean Sea convoy, which had been escorted from Cape Helles by two cruisers and four destroyers. The further to distract Italian attention, an attack and landing on Kastelorizo was simulated by two armed boarding vessels supported by light forces.

As the convoy encountered heavy bombing in the Aegean Sea, it was diverted to the west of Crete, where it was sighted and covered during 28 July by the main fleet, which had itself been subjected to a number of air attacks but suffered no damage. In the course of these operations the Greek merchant vessel Hermione, carrying aviation fuel for the Italian forces in the Dodecanese islands group, was intercepted and sunk. The British ships returned to Alexandria on 30 July.

At the beginning of 1941 there was overall British acceptance of the paramount strategic and operational importance of Malta, and on 21 January the British Chiefs-of-Staff Committee ordained that Air Chief Marshal Sir Arthur Longmore, commanding the British air forces in the Mediterranean and Middle East, must make the air defence of Malta his first priority. In support of this decision, 40 fighters were to be transported by the fleet carrier Furious to Takoradi in West Africa as soon as possible for onward self-ferry. Malta was also to be used as an offensive base, so the island’s Vickers Wellington twin-engined medium bombers pressed ahead with their campaign of attacks on Sicily’s airfields and Italian shipping. An initial success was scored on 27 January after a Short Sunderland four-engined flying boat of No. 228 Squadron reported three merchant vessels off the coast of Tunisia: six Fairey Swordfish single-engined torpedo bombers of No. 830 Squadron then attacked them and torpedoed one ship.

The importance of submarines based at Malta had also been appreciated for some time, and from the beginning of February a force of smaller submarines (Unique, Upholder, Upright, Usk and Utmost) operated in the shallow water off the Tunisian coast in conjunction with a force of larger boats in deeper waters to erode the Italians ability to supply their forces in North Africa.

The British appreciated that the Germans might soon deploy air forces into Sicily and indeed into Dodecanese islands group, and from the latter could attack Aegean Sea traffic and also possibly strike at the Suez Canal. The only sure way of preventing this would be for British forces to capture the Dodecanese islands group before the Germans could implement any such plan. The commanders-in-chief in the Mediterranean had always had this task in mind, but now it became more urgent, and in the middle of January they asked the chiefs-of-staff in London for the 'Glen' class of assault ships to be sent out as soon as possible round the Cape of Good Hope in order that they could be used in operations against the Dodecanese islands group. Meanwhile, they planned a seaborne assault, with forces already available, against the small island of Kásos just to the east of Crete. To agree with this request would have meant cancelling the planned 'Workshop' capture of Pantelleria, but Prime Minister Winston Churchill was adamant that 'Workshop' was more important.

Thus the chiefs-of-staff had to reply on 26 January that the question of the employment of the 'Glen' class ships was still undecided, but that in any case it was not desirable to stir up further Axis interest in the Dodecanese islands group by small seaborne raids until the programme for the whole of the action against the islands had been settled. This veto arrived after the expedition to Kásos had sailed, and Cunningham at once signalled that the intention was not to raid the island but to capture it for good strategic and tactical reasons. The chiefs-of-staff were adamant, however, and Cunningham was compelled to call off the operation only hours before the first landing was to have been effected.

On 20 January the British conceded that growing German air strength on Sicily had now rendered 'Workshop' no longer practicable. The three 'Glen' class ships were due to sail at the end of the month with Naval Base Defence Organisation commando troops and equipment for the Middle East theatre, to be followed two weeks later by the Mobile Naval Base Defence Organisation (more than 5,000 officers and men of the Royal Marines together with anti-aircraft and coast defence equipment) to allow the rapid creation of defences at captured bases. These forces were to be used in any way the local command structure deemed suitable. Thus it seemed to the local commanders-in-chief that while no major effort against the Dodecanese islands group could be attempted before the start of April, they should not leave the islands undisturbed for any length of time, and therefore asked the chiefs-of-staff to overturn their previous ban on raids and the seizure of small objectives. The local commanders argued that the possession of Kásos would enable the airfield on nearby Kárpathos island (known to its Italian occupiers as Scarpanto), lying between Crete and Rhodes, to be shelled and that the capture of Kárpathos would be of great value in the planned attack on Rhodes, and also thought that there was virtue in testing the strength and morale of the Axis forces.

The response of the chiefs-of-staff from London was that the 'Glen' class ships would probably arrive from use from the middle of March, and that a comprehensive overall plan should be developed. The local commanders-in-chief thereupon decided to take Kásos immediately and then to descend on Kastelorizo, and that after the arrival of the 'Glen' class ships their forces would progress to the seizure of Kárpathos as the forward base from which the 'Accolade' assault on Rhodes could be undertaken.

However, the attempt to land on Kásos on 17 February failed for lack of information about the landing places and the exits from them, but on the same day a reconnaissance of Kastelorizo was undertaken by the submarine Parthian in preparation for 'Abstention'. The landing force for this undertaking comprised 200 commandos transported by the destroyers Decoy and Hereward. A 24-man Royal Marine detachment was also delivered into the island’s harbour by the gunboat Ladybird, operating from Famagusta on the island of Cyprus, and further support was afforded by the submarine Parthian.

The flotilla departed Souda Bay on the north coast of Crete during 24 February under the command of Rear Admiral E. de F. Renouf, and the initial plan was to develop a beach-head on the island for 24 hours, after which the arrival of a company of the Sherwood Foresters would allow the consolidation of the British forces on the island as a permanent garrison. The second force would be delivered from Famagusta by the armed boarding vessel Rosaura under escort of the light cruiser Gloucester and light anti-aircraft cruiser Bonaventure.

Before dawn, the Royal Marine commandos started their landing on the main port of the island after a nocturnal gunfire bombardment of the Italian positions had been undertaken by Decoy and Hereward. The Italian presence on Kastelorizo consisted of a 35-man miscellaneous unit of soldiers and men of the Guardia di Finanza in charge of a wireless station. The British troops took the garrison by surprise, seized the radio outpost, took prisoner 12 of the Italians and captured the current Italian code book.

Before the commandos had succeeded in this initial task, however, the Italians had sent an alert to Rhodes, the main Italian air and naval base in the Dodecanese islands group. Only few hours later, Italian bombers appeared and attacked the small island’s harbour, castle and main hills, where the commandos were entrenched. During one of these attacks Ladybird was struck by a bomb, and three of her men were wounded. The vessel, already too short of fuel to continue her mission, was forced to reload the Royal Marines party and to make for Haifa. A consequence of the withdrawal of the gunship was the loss of the commandos' radio link with Alexandria.

The Italian navy’s show of force took place at first light on 26 February. The torpedo boats Lince and Lupo started to land some 240 soldiers at a point to the north of the port, and their 100-mm (3.94-in) guns pounded the British positions. Meanwhile Hereward, warned by the commandos ashore of the Italian naval activity, decided to join Decoy, at the time about 40 miles (65 km) offshore. The local commander ordered the warships to disrupt the Italian landings, but the destroyers was unable to find the Italian warships. Hereward reported that the Italian surface action would made extremely dangerous the landing from Rosaura of the main British force, already compromised by the air attacks on the harbour and, as a result, the landing of the garrison force was postponed and rearranged. The disembarkation would be carried out by the destroyers Decoy and Hero after the company of the Sherwood Foresters had been transboarded from Rosaura.

All the ships were ordered to Alexandria to complete the reschedule. To make matters more difficult for the British, Renouf was taken ill and replaced in local command by Captain H. J. Egerton, Bonaventure's captain. At the same time, high seas also forced the Italian navy to suspend the landings until the morning of 28 February.

The Italian forces already on the island continued to harass the exhausted and isolated British commandos, who had been supplied for only a 24-hour operation.

Under the overall command of Ammiraglio di Divisione Luigi Biancheri and local command of Capitano di Vascello Francesco Mimbelli, the Italian squadron returned some hours later, reinforced by the destroyers Francesco Crispi and Quintino Sella from Léros, as well as the motor torpedo boats MAS-541 and MAS-546, unloading some 300 men and resuming the shelling.

The pressure by air and sea rendered the British troops' situation untenable. Indeed, when the forces from Alexandria arrived on 28 February, Major Cooper, the Sherwood Foresters' company commander, discussed the situation with the other local commanders and realised that without sustained naval and air support, withdrawal was unavoidable. The bulk of the land forces was therefore re-embarked, with about 30 left behind, surrounded and later taken prisoner by the Italians. While providing protection for the retreat, Jaguar was targeted by two torpedoes fired by Francesco Crispi, which failed to hit her. Jaguar responded with her 4.7-in (119-mm) guns, but the jamming of a searchlight prevented her from hitting the submarine. After this last fruitless action, the British force sailed back to Alexandria.

The destroyers Hasty, Jaguar and Nubian, in a further sweep between Rhodes and Kastelorizo, were unable to intercept the returning Italian warships.

The British had lost four men killed and 35 taken prisoner, while the Italians had suffered the loss of 14 men killed and 12 taken prisoner. It was evident that there was much still to be learned about the conduct of this sort of operation, and that the Italians' morale in this quarter was not as low as had been hoped.

The 'Glen' class ships reached the Great Bitter Lake on the Suez Canal during 9 March, by which time all thoughts about the capture of any of the Dodecanese islands group had perforce to be abandoned in the light of the German 'Marita' invasion of Greece. It was not long before the fears of the local commanders-in-chief about the basing of German aircraft on Rhodes was shown to be well founded: toward the end of January German aircraft began to stage through Rhodes to lay mines in the Suez Canal. Thus there had apparently developed a major effect upon the conduct of the war in the Middle East: the passage of the Mediterranean had already been effectively closed, and now the sole remaining link with the Indian Ocean was in danger of being blocked.