in 1975. In 1978, along with the FUNSK Cambodian Salvation Front, the Vietnamese and Ex-Khmer Rouge forces succeeded in toppling Pol Pot's Democratic Kampuchea regime and installing a new government, the People's Republic of Kampuchea. During the Sino-Vietnamese War and the Sino-Vietnamese conflicts 1979–90, Vietnamese forces would conduct cross-border raids into Chinese territory to destroy artillery ammunition. This greatly contributed to the outcome of the Sino-Vietnamese War, as the Chinese forces ran out of ammunition already at an early stage and had to call in reinforcements. While occupying Cambodia, Vietnam launched several armed incursions into Thailand in pursuit of Cambodian guerrillas that had taken refuge on the Thai side of the border. Modern deployment The PAVN has been actively involved in Vietnam's workforce to develop the economy of Vietnam by co-ordinating national defence. It has regularly sent troops to aid with natural disasters such as flooding, landslides etc. The PAVN is also involved in such areas as industry, agriculture, forestry, fishery and telecommunications. The PAVN has numerous small firms which have become quite profitable in recent years. However, recent decrees have effectively prohibited the commercialisation of the military. Conscription is in place for theoretically every male, age 18 to 25 years old, with the exception of the disabled and men who attended universities right after high school. International presence & operations The Foreign Relations Department of the Ministry of National Defence organises international operations of the PAVN. Apart from its occupation of half of the disputed Spratly Islands, which have been claimed as Vietnamese territory since the 17th century, Vietnam has not officially had forces stationed internationally since its withdrawal from Cambodia and Laos in early 1990. Allegations of Vietnamese assistance for overseas leftist insurgencies The effectiveness of the People's Army of Vietnam Special Operation Forces during the Vietnam War saw them instruct various other countries and Marxist rebel groups. From the 1970s to 1990s, they covertly provided training at the PAVN Sapper Training School in via Vietnamese sapper advisors assigned to the Cuban Army's Sapper School in Cuba, and, during the 1980s, by a secret Vietnamese sapper training team stationed in Nicaragua. In addition to training Cambodian, Laotian, Soviet, and Cuban military personnel, their publications revealed that among the foreign revolutionary forces that received training in sapper tactics, bomb-making, and the use of weapons and explosives, were members of the Marxist El Salvadoran FMLN (Farabundo Marti National Liberation Front),