Westmoreland wanted to go north: not into NVN, mind, but Laos. Cut the HCM Trail and bring the NVA into open battle. Lam Son 719 in 1971 was essentially the Westmoreland plan, but with ARVN instead of U.S. Forces. He had a plan involving the 1st Cav, 4th ID, 3rd Marine Division, and Thai forces, and he felt it was workable. Much to his lament, such contingency plans "Gathered considerable dust." The State Department felt it would infringe on Laotian neutrality (guaranteed by the U.S., the Soviets, Red Chinese, and, ironically, Hanoi). Well, excuse me, Mr. Striped-pants diplomat, aren't the NVN already violating Laotian neutrality by (a) staging combat units through Laos to Cambodia and SVN, (b) having base areas for NVA divisions in Laos near the SVN border, and (c) moving war materiel and other supplied down the trail to support said combat units?
Two other things the JCS wanted early on was to mine the NVN harbors (Navy A-1 squadrons were practicing mine drops off of NAS Cubi Point in the Philippines in the 1964-65 period), and do away with the restricted/prohibited target areas around Hanoi and Haiphong: basically, let the air commanders choose targets and strike MiG fields and SAM sites without any concern for killing Soviet advisors at those targets (to give one example).
Essentially, none of the "Graduated Response" stuff that MacNamara and the Whiz Kids favored is what the JCS wanted: "If we're going in, we go all out or we don't go in at all." No bombing pauses, none of this "Hurt them a little to see if they cry Uncle" nonsense. Again, as I've said previously, the goal is not to take NVN (nobody wanted that), but to force them to stop supporting the VC in the South and withdraw NVA forces from SVN. Essentially, force Hanoi to recognize the independence of South Vietnam. That was the goal; but no thanks to LBJ and MacNamara, we didn't go about it very well.