Asia Pacific 1940: Japanese invasion of French Indochina
While Nomonhan and the Molotov-Ribbentrop Pact seemed to put an end to ideas of Japanese expansion north, the outbreak of World War II and the rapid German victories over France and the Netherlands left the European colonies in southeast Asia vulnerable. Japan was quick to exploit this new opening, landing troops in northern French Indochina.
Treaty ports were towns opened to foreign trade by unequal treaties in China. Foreigners operating within treaty ports enjoyed extraterritoriality, being subject to their home country's laws. Unlike concessions such as Hong Kong, these territories were not directly leased by the foreign powers and did not have sizable foreign garrisons.
Treaty ports are not shown in the maps after the 1911 Chinese Revolution in order to give a clearer picture of the chaos in China itself and as by that point their numbers had stabilized. After the revolution, some of the smaller ports were phased out while the others became less important as the situation in China meant that only the concessions could provide foreigners with security. Most, however, still continued on into the 1940s when the Japanese entry into World War II and foreign agreements with China brought them to an end.
See this map for treaty ports in 1907, when the system was at its peak.
By the terms of the Treaty of Tientsin (1858), foreign vessels including warships had the right to free navigation on the Yangtze River. In practical terms, this right extended only as far as Yichang until 1900, when advances in steam navigation allowed access as far inland as Chongqing.
1 Sep 1939 Germany invasion of Poland▲
Using several German-staged incidents as casus belli, Nazi Germany struck Wieluń, Poland, with the Luftwaffe at 04:40 on 1 September 1939—the first blow of World War II. Five minutes later, the German battleship Schleswig-Holstein opened fire on a Polish military transit depot in the Free City of Danzig, with Germany launching an all out attack on Poland’s northern, western, and southern borders later that day.
13 Sep–8 Oct 1939 Battle of Changsha▲
Chinese Nationalists defeat Japanese attack on Changsha
22 Jun 1940 Second Armistice at Compiègne▲
Adolf Hitler and top military officials of Nazi Germany signed an armistice with representatives of the French Third Republic at 18:36 near Compiègne, France—the exact location of the 1918 armistice ending World War I. This new armistice ended French involvement in World War II on the side of the Allies and established a German zone of occupation in northern and western France, leaving the remainder (“Vichy France”) to be governed by the French.
18 Jul 1940 British closure of the Burma Road▲
Yielding to Japanese diplomatic pressure, the United Kingdom closes down the Burma Road as a route of supplies to Nationalist China (at war with Japan since 1937). The closure lasts for three months and is conditional on a Japanese commitment to peace with China.
22–26 Sep 1940 Japanese invasion of French Indochina▲
The Empire of Japan and Vichy French Indochina sign an accord granting Japan the rights to station up to 6,000 troops in Indochina, and to move troops and supplies through Indochina. Within a few hours, columns from the IJA 5th Division cross the border at three places and close in on the railhead at Lang Son, near Longzhou, contravening the new agreement. French Indochinese colonial troops and Foreign Legionaires contest the invasion until 25 September. On the 26th, Japanese forces come ashore at Dong Tac and move on Haiphong, with fighting coming to an end that day.