Asia Pacific 1941: Eve of Pearl Harbor
Germany invaded the Soviet Union in June, but Japan declined to join her ally, resolving instead to occupy the rest of French Indochina. The United States and Britain responded by freezing Japanese assets and stopping oil exports. Without oil, Japan faced the choice of either withdrawing from China or invading the oil-rich East Indies and further provoking the US. By December, Japan had made its decision, mobilizing its fleet for a surprise strike on the US navy.
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.
9 May 1941 Tokyo Peace Treaty▲
The Kingdom of Thailand signs a formal peace treaty with Vichy France in Tokyo, Japan, bringing an end to the Franco-Thai War. By the terms of the treaty, the Vichy French agree to cede the French Indochinese provinces of Battambang, Pailin, Siem Reap, Banteay Meanchay, Oddar Meanchey, Preah Vihear, and Xaignabouli to Thailand.
22 Jun 1941 Operation Barbarossa▲
At 3:15 am the Axis Powers led by Nazi Germany launched the invasion of the Union of Soviet Socialist Republics, bombing cities in a broad arc from Kronstadt to Sevastopol as some three million troops advanced across the border. Within hours the momentum of the Axis attacks had completely destroyed the Soviet organizational command and control, paralyzing every level of command, and it was only at 7:15 am that Soviet leader Josef Stalin announced the invasion to the Soviet Armed Forces and called upon them to act.
23–28 Jul 1941 Operation "FU"▲
In response to a Japanese ultimatum, Vichy France allows Japan to use air facilities and harbors in southern French Indochina. The Japanese proceed to occupy Saigon and other southern cities, with IJN vessels moving into the ports of Saigon, Tourane, and Camranh Bay.
26 Jul 1941 Freezing of Japanese assets▲
Following Japan's rejection of a United States-sponsored plan to withdraw from most of China and French Indochina and a Japanese agreement with Vichy France to allow Japanese troops into southern Indochina, the US froze Japanese assets. The United Kingdom and the Netherlands followed suit, depriving Japan of 90% of its oil imports.
26 Nov–7 Dec 1941 Hawaii Operation▲
Japanese strike force sails from Kurile Islands for Pearl Harbor
1 Dec 1941 Japan rejects terms offered by US government▲
Japan rejects terms offered by US government
5 Dec 1941 Yangtze Patrol dissolved▲
With US relations with Japan deteriorating and the situation in China becoming increasingly tense, most of the vessels of the Yangtze River Patrol were withdrawn to Manila by early December 1941. On 5 December, the patrol was formally dissolved, not to be resurrected until the Japanese surrender in China. The retreat did the ships little good, however, as they were either captured or scuttled when the Japanese overran the Philippines the following year.