Full independence was achieved in 1953 under the rule of King Sisavang Vong. The monarchy was opposed by former nationalist guerrillas organised into the Laotian Patriotic Front (LPF) whose fighters, the Pathet Lao, formed an alliance with the Viet Minh (later Viet Cong) nationalists in neighbouring Vietnam to expel the residual French, and later to counter US influence in the region and the regimes supported by them. Despite repeated efforts, both before and after the communist takeover in 1975, the Chinese failed to exert any significant influence over the country. Indeed, after 1975, Laos became dependent on military and economic assistance from Vietnam, China's enemy. In the late 1980s, however, tension between China and Laos at last began to ease: diplomatic relations (which had been severed in the late 1970s) were restored in December 1987, and cultural and bilateral trade agreements signed.