'Pike' (i) was a British unrealised proposal to use bombers to cripple Soviet oil production in the trans-Caucasus region during the period before the 'Barbarossa' invasion ended the German/Soviet Non-Aggression Treaty of August 1939 (spring 1941).

Conceived under the leadership of Air Commodore John Slessor, the planned 'Pike' (i) reflected British and French fears late in 1939 and early in 1940 that the USSR was in effect a German ally. 'Pike' (i) was therefore schemed as the way to destroy the Soviet oil industry, thereby causing the collapse of the Soviet economy and thus depriving Germany of Soviet resources.

Initial planning began shortly after the Soviet invasion of eastern Poland in September 1939 as the Germans took the western part of the country in 'Weiss' (i), and was deemed to have gained greater importance after the Soviet launch of the 'Talvisota' in December 1939 to seize parts of eastern Finland. The Allied plans included the seizure of northern Norway and Sweden, and an advance into Finland to combat Soviet ground and naval forces in Finland and the Baltic. It was quickly appreciated that such plans would be both costly and ineffective in dealing with the German threat, however, and therefore they were trimmed to the seizure of Norway and the iron ore mines in northern Sweden.

Meanwhile British and French economic warfare specialists identified a German dependence on fossil fuels imported from the USSR as a vulnerability which the Allies could exploit. Despite initial opposition by some politicians, the French government ordered Général d’Armée Maurice Gamelin, the commander-in-chief of the French armed forces, to develop a 'plan of possible intervention with the view of destroying Russian oil exploitation', while William C. Bullitt, the US ambassador to France, reported to his government that the French considered that attacks by French air forces in Syria against Baku would be 'the most efficient way to weaken the Soviet Union'. According to Gamelin’s report, submitted on 22 February 1940, an oil shortage would cripple the Soviet army and air force, as well as Soviet collective farming, causing possible widespread famine and even the collapse of the USSR, and affirming that 'Dependence on oil supplies from the Caucasus is the fundamental weakness of Russian economy. The armed forces are totally dependent on this source also for their motorised agriculture. More than 90% of oil extraction and 80% of refinement is located in the Caucasus (primarily Baku). Therefore, interruption of oil supplies on any large scale will have far-reaching consequences and could even result in the collapse of all the military, industrial and agricultural systems of Russia.' An important source of raw materials would also be denied to Germany with the destruction of the oil fields.

Serious British preparations were started after the end of the 'Talvisota' winter war in March 1940. By April, detailed British plans to attack oil production centres in the Caucasian cities of Baku, Batumi and Grozny had been completed, and envisaged the use of bombers operating from bases in Iran, Turkey and Syria. The plans were designated 'Western Air Plan 106' and codenamed 'Pike' (i).

On 28 March 1940, the British and French discussed their overall military strategy and agreed on the mining of Norwegian western territorial waters in 'Wilfred'. But the British and French could not reach agreement on the bombing of Baku. The French proposed an acceleration of the Allied planning, but the British were more cautious, fearing a possible Soviet/German alliance in the event of an Allied attack on the USSR.

The Soviet leadership also anticipated the Allies' actions and, between 25 and 29 March, the staff of the Transcaucasian Military District undertook a map exercise in which the 'Black' forces, continuing their actions against the 'Brown' forces on the western front, co-operated with the 'Blue' and 'Green' forces in attacking the 'Red' forces in the Caucasus region before being driven back by the 'Red' forces, which then began a counter-offensive toward Erzurum in Turkey and Tabriz in Iran.

While some historians do not take the British plans seriously, seeing only contingency thinking in them, Russian historians note that the British and French military staffs had developed strategic plans for an invasion of the USSR from the south, but that their governments lacked the political will to make the appropriate decision.

In March 1940 the British undertook secret photo-reconnaissance flights of the proposed target areas in the USSR using high-altitude high-speed stereoscopic photography of the type pioneered by Sidney Cotton. Using specially modified and unmarked Lockheed Model 14 Super Electra aircraft painted in a special blue camouflage scheme developed by Cotton, who led the RAF’s Photographic Development Unit, the Secret Intelligence Service launched the high-altitude reconnaissance flights from the RAF base at Habbaniyah in Iraq. One such mission was flown on 30 March 1940: flying over the mountainous region of south-eastern Kurdistan, across the coast of the Caspian Sea then to the north in the direction of Baku, the flight penetrated Soviet airspace at 11.45, after a four-hour flight, then loitered for one hour while making six runs with its 14-in (356-mm) camera, and left Baku at 12.45 for its return flight to Habbaniyah. Another flight from Habbaniyah on 5 April, this time crossing Turkish airspace, reached the Batumi area on the east coast of the Black Sea. The aeroplane was met by Soviet anti-aircraft fire, and a Soviet fighter also attempted to intercept it. However, the British had obtained everything they needed for photo interpretation purposes and for mapping the Soviet petroleum centres.

Analysis of the photography by the Photographic Development Unit revealed that the oil infrastructure in Baku and Batumi were particularly vulnerable to air attack as both could be approached from the sea, so the more difficult inland target of Grozny would be bombed first to exploit the element of surprise. Oil fields were to be attacked with incendiary bombs, while tests conducted at the Royal Arsenal at Woolwich revealed light oil storage tanks at the oil processing plants could be detonated with high explosives.

As of 1 April, four squadrons comprising 48 Bristol Blenheim Mk IV light bombers were transferred to the Middle East Command, supplemented by a number of obsolescent Vickers Wellesley long-range bombers for night missions. A French force of 65 Martin Maryland bombers and a supplementary force of 24 Farman F.222 heavy bombers was allocated for night operations. The French were preparing new airfields in Syria, and planned to have these ready by 15 May.

The Allies expected that the campaign would last three months, and more than 910 tons of ordnance were allocated to the operation: 404 armour-piecing bombs, 554 500-lb (227-kg) and 5,188 250-lb (113-kg) general-purpose bombs, and 69,192 4-lb (1.8-kg) incendiary bombs.

The German success in 'Gelb' and 'Sichelschnitt' and the resulting fall of fall of France effectively ended 'Pike' (i). The Germans captured a train at La Charité sur Loire and discovered boxes of secret documents including some associated with 'Pike' (i). On 4 July the Germans released excerpts of the captured documents, asserting that 'Germany must be credited with saving these other states [including the USSR] from being drawn into this chaos by Allied schemings…because she took timely counter-measures and also crushed France quickly.' 'Pike''(i) was thereby compromised and the planned launch of a strategic Anglo-French bombing campaign against Soviet targets was put on hold and eventually abandoned.

After Germany’s 'Barbarossa' invasion of the USSR in June 1941, the British started to update 'Pike' (i) as 'Raspberry' to serve as a contingency plan for possible implementation should the Germans seize the Caucasian oilfields.