During the Laotian Civil War, Xiangkhouang was the scene of extensive ground battles and intense aerial bombardment due to its strategic importance. Houaphanh and Xiangkhouang Provinces had been strongholds of the Pathet Lao forces and their Vietnamese allies. The heavy aerial bombardments to neutralize those forces or to drop unused ordnance after returning from missions in Vietnam turned the Laos into the most heavily bombed nation in world history.