Tientsin Incident Background . On July 30 , 1937 , Tianjin fell to the Empire of Japan as part of a military operation in the Second Sino - Japanese War , but was not entirely occupied , as the Japanese for the most part continued to respect the integrity and extraterritoriality foreign concessions in Tianjin until 1941 . In the summer of 1939 , a major crisis in Anglo - Japanese relations occurred with the Tientsin Incident . On April 9 , 1939 the manager of the Japanese - owned Federal Reserve Bank of North China was assassinated by Chinese nationalists at Tientsin ' s Grand Theatre . The Japanese accused six Chinese men living in the British concession of being involved in the assassination . The local British police force arrested four of the six , and handed them over to the Japanese with promises that they would not be tortured and would be returned to British custody within the next five days . Under torture , two of the four confessed to being involved in the assassination . Although the confessions were obtained by torture , the local British police concluded that the accused were involved in the assassination . Once the four men returned to British custody , Madame Soong May - ling , the wife of Chiang Kai - shek admitted to the British Ambassador in Chongqing , Sir Archibald Clark - Kerr that the accused assassins were Chinese operatives involved in resistance work , and lobbied Clark - Kerr to prevent the accused being returned and executed by the Japanese . The local British consul , Mr . Jamieson , had not kept London well - informed on the details of the case , especially the fact that he had promised the Japanese that he would hand over the accused assassins . The British Foreign Secretary Lord Halifax , hearing that the confessions had been obtained by torture , ordered that the accused assassins should not be handed back to the Japanese . The commander of the Japanese North China Army , General Masaharu Homma , was regarded as friendly by the British , but his Chief of Staff , General Tomoyuki Yamashita , was known to be a believer in abolishing all the Western concessions in China . Since early 1939 , General Yamashita had advocating ending the British concession in Tientsin , and he used the British refusal to turn over the alleged assassins to convince his superiors in Tokyo to order a blockade of the concession . The Blockade . On June 14 , 1939 , Imperial Japanese Army forces of the Japanese Northern China Area Army surrounded and blockaded the foreign concessions over the refusal of the British authorities to hand over four Chinese who had assassinated a Japanese collaborator ( a customs official ) , and had taken refuge within the British concession . Anyone wishing to leave or enter the concession was publicly strip - searched by Japanese soldiers while food and fuel were not permitted to enter the concession . The Japanese government declared the issue of the accused killers was not the point of the blockade , and that handing over the four would not end the blockade . A Japanese spokesmen stated " The arrow is already off the bow and therefore the question cannot be settled by the mere transfer of the four suspect assassins " . The Japanese demanded that the British government turn over all silver reserves belonging to the Chinese government within British banks to them , forbade all anti - Japanese radio broadcasts from anywhere in the British Empire , ban school textbooks that the Japanese government considered offensive , and ended the issuing of " fapi " currency . For a time , it appeared likely that the situation would precipitate an Anglo - Japanese war , especially when inflammatory reports of insulting treatment by the Japanese of British subjects attempting to enter or leave the concession appeared in the British press . British public opinion was especially offended by reports of British women forced to strip in public at bayonet - point by Japanese soldiers , which led to a flood of " Yellow Peril " stereotypes being widely invoked in the British media . British Admiral of the Fleet Sir Roger Keyes considered the situation to be tantamount to a declaration of war . At the time , Tianjin had a population of approximately 1500 British subjects ( half of whom were soldiers ) , and was a major centre for British trade in northern China . The British Prime Minister Neville Chamberlain considered the crisis to be so important that he ordered the Royal Navy to give greater attention to a possible war with Japan than to a war with Germany . Resolution . On June 26 , 1939 the Royal Navy and the Foreign Office reported to the British Cabinet that the only way of ending the blockade was to send the main British battle fleet to Far Eastern waters , and that given the current crisis vis - a - vis Nazi Germany threatening Poland , this was militarily unadvisable . In addition , Chamberlain faced strong pressure from the French not to weaken British naval strength in the Mediterranean , given the danger that Benito Mussolini might honor the Pact of Steel should war break out in Europe . Following an unsuccessful effort to obtain a promise of American support ( who told the British that the United States would not risk war with Japan for purely British interests ) , Chamberlain ordered Sir Robert Craigie , the British Ambassador in Tokyo , to find any way of ending the crisis without too much loss to British prestige . During the course of negotiations with the Japanese , Craigie took advantage of divisions within the Japanese leadership , especially between the Prime Minister , Baron Hiranuma Kiichirō who wished for a greater degree of control over the military and the military itself , which wanted less civilian control . In addition , there were divisions within the Japanese government between one fraction that wanted to use the crisis to start a war with Britain , and another that argued that , given the war with China plus the border war with the Soviet Union , starting a third war at this time was unwise . At the same time , the British applied economic pressure on the Japanese by raising their tariffs on Japanese goods . Though Craigie knew that the dispatch of the British battle fleet had been ruled out , he often implied during his talks with the Japanese that Britain would go to war to end the blockade . Through his policy of bluff , plus divided counsel within different factions within the Japanese government ( which Craigie exploited ) , Craigie was able to persuade the Japanese to back down from their more extreme demands – such as the demand to turn over the Chinese silver in British banks – while agreeing to submit to the Japanese demand to hand over the Chinese suspects . On August 20 , 1939 the British thus chose to turn over the four Chinese fugitives to end the standoff ; the Chinese were later executed by the Japanese . Consequences . The Tientsin Incident highlighted the gap between the foreign policy of Japan ' s civilian government , as expressed through Japanese ambassador to the Court of St . James , Mamoru Shigemitsu , who attempted to defuse the situation through negotiation , and the Japanese Army under the War Minister , General Hajime Sugiyama , who was escalating the situation through demands for an end to the foreign concessions in Tientsin altogether . The British historian D . C . Watt argued that the partial diplomatic victory by the Japanese helped to keep Japan neutral during the first year of World War II . It also highlighted the weakness of the United Kingdom ' s position in Asia , both militarily , and diplomatically with its failure to enlist the United States to take a stronger position in its support .