One of the central frustrations of the US military during the conflict was the Democratic Republic of Vietnam's (North Vietnam) use of Laos and Cambodia as logistical conduits and base areas. During the administration of President Lyndon B. Johnson, the US military was generally not allowed by its civilian commanders to widen the war by attacking the supply routes and sanctuaries in both countries due to their ostensible neutrality. An attempt was made to capture or destroy the headquarters during Operation Junction City, a massive search and destroy operation launched in the border region in February and March 1967.