What is Battle of Route Coloniale 4?
[[File:Batalla de Cao Bang.jpg|thumb|Campaign performance]] '''Battle of Route Coloniale 4''' was a campaign in the [[First Indochina War]] carried out by the Việt Minh Army from 16 September to 17 October 1950 to break the isolation of the Việt Bắc base, clear the Vietnam-China border Bridge to receive aid. Another objective was to expand the base and destroy some of the French garrison force, experimenting with tactics for the [[People's Army of Vietnam]] at that time with little experience in combat. ==Background== In 1949 the French Army was still unable to advance into the Việt Bắc area. The control of the Northern Delta was slow but unstable. Việt Minh gradually reorganized its apparatus and forces, and began organizing large-scale battles against French forces.During the five years of the war against the French in isolation, the Việt Minh actively expanded relations to seek international support. On October 1 1949 the [[People's Republic of China]] was established and quickly recognized and established diplomatic relations with the [[Democratic Republic of Vietnam]].<ref>{{cite book| last = Jr| first = Ronald B. Frankum| title = Historical Dictionary of the War in Vietnam| url = https://books.google.com/books?id=WLcG5Cdw-NIC&pg=PA512| date = 2011-06-10| publisher = Scarecrow Press| language = en| isbn = 978-0-8108-7956-0 }}</ref> Then on January 18, 1950 the [[Soviet Union]] and Eastern European countries recognized and established diplomatic relations with the Democratic Republic of Vietnam. The prestige and military capabilities of the Việt Minh Front are growing in the people. During the same five years, the Việt Minh also adopted overseas Vietnamese organizations in [[France]] and left-leaning organizations to fight politics strongly influencing the French people's rising resistance to Indochina War. France fell into an unprecedented political crisis. The Vietnamese State lacked credibility among the people as a puppet government, and its army was too weak to cooperate with French troops in Indochina