s taying the c ourse 233became apparent back in Washington if not to MACV. Cutting off
resupply of the enemy rested entirely on air interdiction. Yet air attacks
could do no more than hamper infi ltration down the Ho Chi Minh
Trail. And if the Americans and South Vietnamese could not isolate the
battlefi eld, the communists could maintain their force-in-being, pos-
sibly even expand it. Th e result would be a military stalemate in the
conventional war, neither side able to defeat the other. Ultimately, the
outcome would be determined by whichever side had greater staying
power, and, loath though Johnson was to admit it, that equation in turn
would disadvantage the United States as the external combatant.
Again and again, American military commanders pressed to remove
the restrictions on U.S. military operations, but the president and his
civilian advisors resisted. Th rough 1966 and 1967, the administration
reluctantly added new bombing targets to the list, until nearly all the
worthwhile military ones were struck. It was still not enough to satisfy
the JCS: the Chiefs wanted to mine Haiphong harbor, the principal
DRV port through which many supplies arrived, and extend bombing
to near the Chinese border to block rail deliveries, too. McNamara and
other civilian leaders continued to insist that the risk of widening the
war was too great and cautioned that world opinion would turn even
more sharply against the United States, already seen to be bullying a
small nation. Johnson sided with his civilian advisors and became frus-
trated when, amid mounting evidence of a stalemate on the ground, the
JCS seemed unable to recommend anything better than more bombing.
Similarly, military suggestions to allow American ground forces to
attack communist sanctuaries in Cambodia and block enemy supply
lines through Laos by assaulting westward from the northern neck of
South Vietnam met the same political objections as earlier—such
actions, Washington repeated, posed too much danger of expanding the
war. (Later events would demonstrate that both sides were mistaken
about the eff ects of removing the limits on military operations.)
Th e attrition strategy also fell afoul of political constraints. Early
estimates minimized the number of NVA troops available for service in
South Vietnam, so it seemed possible—if just barely—that communist
soldiers might be killed off faster than they could be replaced. It soon
became painfully clear, however, that American intelligence had greatly
underestimated Hanoi’s will and capacity to reinforce its army in the