Since 1931, between China and Japan is constantly armed conflicts broke out, Japan has sought to make a demilitarized buffer zone between Manchukuo and China. In 1932, China was forced to demilitarize Shanghai, in 1933, the inhabitants of the country of the rising sun once again stormed China captured the province of Jehol and forced the Chinese government to agree to a demilitarized zone between the wall and the stateliness of China Beijing-Tianjin area. In addition, residents of the country of the rising sun is constantly interfered in China's internal affairs by supporting the rebel generals and governors, so as not to give China to become a strong country.
In 1937, a full-scale war, which ended in 1945. Chinese historians believe that the concrete July 7, 1937 began the second global war, not the first of September, 1939.
The reason for the war served as an incident at Marco Polo Bridge (Lugoutsyao) July 7, 1937 — During the night the teachings of the Japanese fighter was gone. Living in the country of the rising sun claimed to extradite him or keep them for his research into the fortress Vanpin, the Chinese refused, began firing. Then, after brief negotiations, the residents of the country of the rising sun began full-scale war — July 26, 40000th Japanese army defected in coming. July 28-30 were captured Beijing, Tianjin, until the end of the year — Shanghai, Nanjing. In Nanjing residents of the country of the rising sun made a terrible massacre, killing more than 200 thousand Chinese. The Chinese are inferior to people of the country of the rising sun in arms skills of performance, discipline, their were no modern navy and air force.

The position of the USSR
Moscow in turn all the 30 years of politically supported China. USSR was profitable prolong the war, so the Chinese can be kept as a little longer, this attention Land of the Rising Sun was delayed by the South's strategic direction. Japan frittered forces to war, weakened strike force on the border with the Soviet Union.
Because Stalin began to rally the Chinese Communist Party from the government of Chiang Kai-shek to confront a common enemy.

Major milestones
— In August 1937, a contract was signed between China and the Soviet non-aggression pact, the Kuomintang government requests to provide real help.
— Due to the virtually complete loss of sea routes, China asks Moscow to assist in the construction of the highway Sarah Ozek — Urumqi — Lanzhou, the Russian government agreed, Moscow began to supply the Chinese weapon, ammunition, medical supplies, aircraft and so on. Everyone in the credit score.
— Due to the serious neuvvyazkami with the Air Force, China begin to supply aircraft to assist in the development of the Chinese air force targeted Russian military spec. Just 1937-1940 years, China visited the "mission" 300 military experts. Total Russian people worked more than five thousand people — pilots, instructors, engineers, doctors, teachers, etc., in the autumn of 1937, China sent 225 aircraft, including 62 bombers SB, and 89 aviation professionals to teach Chinese. Aircraft ferried from Irkutsk through Mongolia to the airport in Wuhan province Hupey. Identification mark of a Russian volunteer pilots were 12-spoke star Kuomintang government. At the airport Nanjing focused two battle groups: 23-16 fighter under the command G.M.Prokofeva and 20 SB bombers under the command N.M.Kidalinskogo. At the airport Hankou was a group of 31 bombers under the command of Security F.P.Polynina. Total to June 1941 Alliance aircraft delivered to China in 1250, 10 of thousands of bombs.

— November 21, 1937 took place the first Russian pilots dogfight with the Japanese Air Force 7 of our 20 aircraft stormed the Japanese shot down three without loss.
— At the end of 1938 in Hong Kong from Sevastopol brought 82 T-26 tanks and other weapons.
— In February 1938, a squadron of bombers high-SB-2 under the command stormed Polynin Japanese airfield in the Shanghai area, destroyed 30 enemy fighters.

From left to right: AA Shumejko, FP Polynin, GA Ivanov.
— February 23, 1938 28 SB-2 under the command of FP Polynin made a raid on the peninsula Formosa, Russian bombers stormed the Japanese airfield and port Xinzhou Taipei. The Japanese command believed that the base in Formosa invulnerable to Russian pilots, and there are huge supplies concentrated fuel and aviation assets. Planes brought to Formosa in the containers were collected and distilled in Shanghai. In the end, the pilots killed 40 enemy aircraft, three in store fuel burned, destroyed the airfield. November 14, 1938 for their courage and heroism in battle on the ground in China Fedor Petrovich Polynin received the title of Hero of the Russian Union of the Order of Lenin.
— In March 1938, China and the Soviet Union signed a trade contract, Moscow has granted a loan of 50 million dollars to implement. Bomber squadron commanded by Timothy Khryukin stormed the Yellow River (in another version — on the Yangtze) Japanese light aircraft carrier "Yamato Maru" (in other versions — on aircraft carriers or transport ship carrying aircraft) and drowned him. Timothy T. Khryukin February 22, 1939 received the title of Hero of Russian Union.

Khryukin Timothy T., twice Hero of the Soviet Union.
— In April 1938, construction was completed on the highway to the border with the USSR (in Xinjiang Province), began a large supply of weapons, including 62 fighter-15, lot of guns, along with advisers-gunners.
— At the end of May 1938 our fighters shot down 15 Japanese bombers, have lost one aircraft.