244 { China’s Quest
DRV. Third, China was prepared for the eventuality of war with the United
States, and Washington should not think that China would back down in the
face of US provocations because of China’s weakness. Fourth, if the United
States provoked war with China, that war would know no boundaries.^24 This
last point was an implicit threat to spread a war triggered by Vietnam into
Laos, Thailand, and perhaps even Korea. When Ayub Khan later canceled his
scheduled visit to Washington, Zhou repeated his four-point message to the
president of Tanzania and other foreign leaders. China’s representatives in
Warsaw also reiterated the message.
President Johnson’s fear of sparking “another Korea” exercised a signif-
icant influence on the US campaign against the DRV. Although US mas-
tery of the sea approaches to the DRV was absolute, the United States did
not—until 1972—impose a naval blockade or embargo. From 1964 until early
1972, Chinese, Soviet, East European, and some West European ships carried
cargos of civilian and military goods to DRV ports, often passing within view
of US warships. This forfeiting of US naval supremacy was an immense ad-
vantage to Hanoi. US forces monitored closely all maritime traffic with the
DRV, and could easily have shut it off—as they did in less than one day in the
spring of 1972 when finally given the order to mine DRV harbors.
Regarding the air campaign, the United States did not—again until
1972—wage all-out air war against the DRV. In 1964, Air Force Chief of Staff
Curtis LeMay recommended that all available US air power be used to attack
the DRV as abruptly, intensely, and completely as possible to destroy within
the shortest possible time the country’s ability to make war. US leaders ruled
out this approach, once again until 1972, in favor of a slow and incremental ex-
pansion of the scope and intensity of bombing. This allowed Hanoi to disperse
and conceal potential targets, and use frequent pauses in bombing—intended
by the United States to signal the limited nature of US aims and allow VWP
leaders to “cool down”—to conduct essential redeployments. It also gave
Hanoi time to build up what would eventually become a world-class air de-
fense system that posed deadly threat to US planes. The United States did
not carpet bomb or fire bombed North Vietnamese population centers as it
had Japanese cities in 1945. Under US war planning, DRV city centers were
excluded from bombing, and a “donut” area around those centers was subject
to heavily restricted bombing. This too was a boon to Hanoi. Restricted and
no-bomb areas became favored locales for PAVN supply dumps, transport
depots, and command centers. Some of those restrictions were incrementally
lifted in line with the strategy of gradual escalation.
Further US restrictions on the war against Hanoi involved the nondeploy-
ment of US ground forces into Laos as prohibited by the 1962 “neutralization”
agreement—even though the enemy’s vital trails ran through the south-
eastern portion of that country.^25 Instead, the United States relied on indige-
nous Laotian anticommunist forces (especially among the Hmong mountain