In the late 1930s, Seversky aircraft exported twenty two-seat 2PA-B3 to Japan for operational service by the Imperial Japanese Navy Air Service as the A8V1 Type S Two Seat Fighter. The aircraft were imported as a result of Japanese anxiety over escalating losses for their unescorted strategic bombing raids with Type 96 G3M bombers deep into China from bases in Formosa (Taiwan) which had begun in 1937. The purchase contract for the Seversky 2PA-B3, construction numbers 122 through 141 had been negotiated secretly but was to cause controversy in the US and subsequent difficulties in Seversky's relationship with the US government and military. Sources differ on exactly when the aircraft were delivered, but it must have been at least prior to October 1938 (see below). Design and development The origins of the Seversky P-35 single-seat fighter trace back to the Seversky SEV-3 amphibian, which was developed into the Seversky BT-8 basic trainer. Seversky's chief designer, Alexander Kartveli, also proposed a two-seat fighter derivative, the SEV-2XP. This was powered by a Wright R-1670 radial engine. It had fixed landing gear in aerodynamic spats and was armed with one and one forward-firing machine guns plus an additional machine gun for rear defence. When the USAAC announced a competition for a new single-seat fighter in 1935, Seversky sent the SEV-2XP, confident it would win despite being a two-seater. However, the aircraft was damaged on 18 June 1935 during its transit to the fly-offs at Wright Field. The Air Corps delayed the fly-off until March 1936, which allowed Seversky time to rework the fighter into the single-seat SEV-1XP with retractable landing gear and re-engined with the Wright R-1820 radial. In what proved to be an unpopular move for Seversky, twenty 2PA-B3s were sold to the Japanese Navy, which briefly employed them in the Second Sino-Japanese War as Navy Type S Two-Seat Fighter or A8V1 (Allied codename "Dick"). Two demonstrators ended up in the USSR; although a manufacturing licence was also bought, the Soviets undertook no production. Sweden ordered 52 2PAs (known as the B 6), but only two were delivered before the remaining 50 were impounded in 1940 and put into service with the USAAC as the AT-12 Guardsman advanced trainer. On 18 June 1940, United States declared an embargo against exporting weapons to any nation other than the United Kingdom. Operational history The Seversky two-seat fighters were to be used as long-range escort