Westmoreland (COMMACV) said before he died that there was a plan that would've forced NVN to quit the war; invade Laos and cut off the Ho Chi Minh Trail. Three divisions (1st Air Cav, 4th ID, and 1st Marine) were to move into Southern and Central Laos, as far as Tchepone, and "seize, occupy, and defend" all known and suspected NVA base areas. A Thai division was to come in (there was a Thai brigade that fought in the Saigon and Cambodian border areas from 1967-70) and link up with the forces coming in from SVN. And to block the trailhead: an Amphibious and airborne assault (173rd Airborne Brigade and 3rd Marine Division) to land in NVN north of Vinh, and advance to cut off the Mu Gia Pass, with Army forces following up behind the Marines and Airborne. Result: the trail is blocked, and the VC/NVA down south are isolated from the North. The GAME WARDEN/MARKET TIME naval interdiction campaign prevents moving any significant supplies from the North via sea, and fearful of U.S. action, Sianhouk orders the NVA and VC in Cambodia out of the country. To try and reopen the trail, the NVA in the North has to manuver and fight conventionally, not as insurgents. U.S. air and naval superiority makes it impossible to retake the Pass, and Hanoi throws in the towel. The only opposition to implementing the plan was (as usual) from the State Department: "Laos is neutral, and we'd be violating Laotian neutrality." Well, Mr. Striped-pants diplomat, what do you think the North Vietnamese Army's doing in Laos? They sure as hell aren't tourists. And there was no way the Soviets were going to intervene, and the Chinese are busy with their own internal problems (read: Cultural Revolution). Could it have worked: maybe. But we'll never know.