Yangtze patrol

Yangtze Patrol (YangPat)
USS Panay, a U.S. Navy river gunboat, of the "Yangtze Patrol" commissioned in 1928, as she sinks on the Yangtze River near Nanking, China in December 1937, after being attacked by Japanese aircraft.
Planned by	United States
Objective	protect United States interests, in Yangtze River treaty ports and U.S. citizens in China, from Chinese insurgents and river pirates
Date	1854–1949
Executed by	U.S. Navy
Outcome	avoiding internal Chinese conflicts in mid 19th-mid 20th century, except for World War II

The Yangtze Patrol, also, known as the Yangtze River Patrol Force and Yangtze River Patrol or YangPat and ComYangPat, from 1854–1949, was a prolonged naval operation to protect American interests in the Yangtze River's treaty ports. Initially the patrol was carried out by ships of the United States Navy's East India and Asiatic Squadrons. In 1922, the "YangPat", an abbreviated shortening of Yangtze Patrol, was established as a formal component and assigned to the Asiatic Fleet. Under the unequal treaties, the United States, Japan, and various European powers, especially the United Kingdom, who had been on the Yangtze, since 1897, were allowed to cruise China's rivers. They also, patrolled coastal waters, protecting U.S. citizens, their property, and Christian missionaries. The Yangtze is China's longest river, and very important for commerce. Ocean-going vessels were able to proceed as far upstream as the city of Wuhan. This squadron-sized unit cruised the waters of the Yangtze as far inland as Chungking, more than 1,300 mi (2,100 km) from the sea, and occasionally far beyond.

As a result of the "unequal treaties" imposed on China by Great Britain and other European powers after the First Opium War (1839–1842) and Second Opium War (1856–1860), China was opened to foreign trade at a number of locations known as "treaty ports" where foreigners were permitted to live and conduct business. Also, created by the treaties was the doctrine of extraterritoriality, a system whereby citizens of foreign countries living in China were subject to the laws of their home country, not those of China. Most favored nation treatment under the treaties assured other countries of the privileges afforded Great Britain, and soon many nations, including the United States, operated merchant ships and navy gunboats on the waterways of China.