Massive aerial bombardments against the PAVN/Pathet Lao forces were carried out by the United States to prevent the collapse of the Kingdom of Laos central government, and to deny the use of the Ho Chi Minh Trail to attack US forces in South Vietnam. Between 1964 and 1973, the US dropped two million tons of bombs on Laos, nearly equal to the 2.1 million tons of bombs the US dropped on Europe and Asia during all of World War II, making Laos the most heavily bombed country in history relative to the size of its population; ''The New York Times'' notes this was "nearly a ton for every person in Laos". Some 80 million bombs failed to explode and remain scattered throughout the country, rendering vast swaths of land impossible to cultivate and killing or maiming approximately 50 Laotians every year. Because of the particularly heavy impact of cluster bombs during this war, Laos was a strong advocate of the Convention on Cluster Munitions to ban the weapons and was host to the First Meeting of States Parties to the convention in November 2010.