Asia Pacific 1939: Nomonhan Incident
A second Soviet-Japanese dispute broke out on the Mongolian border in May 1939, culminating in the Soviet defeat of Japanese forces at Nomonhan in August. At the same time, the Soviets signed the Molotov-Ribbentrop Pact, a non-aggression treaty with Japan's erstwhile ally Germany.
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.
9–11 Feb 1939 Hainan Island Operation▲
Japan occupies Hainan Island
4 Apr 1939 Japan occupies Spratly Islands▲
Japan occupies Spratly Islands
11 May–16 Sep 1939 Battles of Khalkhin Gol▲
Border clashes between Japanese troops in Manchukuo and Soviet Union, culminating in Japanese defeat at Nomonhan
24 Jun 1939 Siam becomes Thailand▲
In the first of a series of Cultural Mandates issued by the government of Field Marshal Plaek Pibulsonggram during his first period as Prime Minister and military dictator, the Kingdom of Siam is officially renamed as the Kingdom of Thailand. From now on in English, the country is called 'Thailand' and the people called 'Thai'.
23 Aug 1939 Molotov-Ribbentrop Pact▲
German foreign minister Joachim von Ribbentrop and Vyacheslav Molotov, his Soviet counterpart, signed the Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics in Moscow. The pact provided a guarantee that neither of the two powers would take up arms against the other, as well as secretly dividing eastern Europe between them.