Sino-Soviet conflict (1929)

The Sino-Soviet conflict of 1929 (Chinese: 中東路事件; Russian: Конфликт на Китайско-Восточной железной дороге, lit. 'Conflict on the Chinese Eastern Railway') was an armed conflict between the Soviet Union and the Chinese warlord Zhang Xueliang of the Republic of China over the Chinese Eastern Railway (also known as the CER). The conflict was the first major combat test of the reformed Soviet Red Army, which was organized along the latest professional lines, and ended with the mobilization and deployment of 156,000 troops to the Manchurian border.

Source: Wikipedia — Sino-Soviet conflict (1929) (CC BY-SA 4.0)