Editing Operation Linebacker (section)

==Operation Pocket Money==
{{Main|Operation Pocket Money}}
On 27 April, ARVN defenses in [[Quảng Trị Province]] began to collapse. Due to conflicting orders from their high command, ARVN units joined an exodus of refugees heading southwards, abandoning [[Quảng Trị]] city.<ref>Dale Andrade, ''Trial by Fire''. New York: Hippocrene Books, 1995 p. 52.</ref> PAVN forces entered the city on the same day as the meeting between Kissinger and Le Duc Tho. The PAVN offensive had become a massive conventional military operation that was being conducted on three fronts simultaneously, involving the equivalent of 15 divisions and 600 tanks.<ref>Dave Richard Palmer, ''Summons of the Trumpet'', New York: Ballentine, 1978, p. 317.</ref> As the North Vietnamese continued to gain ground in three of South Vietnam's four military regions, the U.S. Joint Chiefs of Staff updated their contingency plans (drawn up before the bombing halt of 1968) for the resumption of bombing in the north and recommended it to the President, who approved it on 8 May.<ref name="Tilford, p. 233">Tilford, p. 233.</ref>

Shortly after his inauguration, Nixon had ordered the preparation of a contingency plan, one that would hopefully bring the Vietnam War to an end.<ref name="Morocco, p. 130">Morocco, p. 130.</ref> [[Duck Hook|Operation Duck Hook]] was to include an invasion of the North and included a proposal to mine its major harbors.<ref>Fulghum and Maitland, p. 144.</ref> The plan had been shelved at the time as too extreme but it had not been forgotten. The USN had also been updating its own contingency plans for just such a mining operation since 1965. On 5 May, Nixon ordered the Joint Chiefs to prepare to execute the aerial mining portion of the ''Duck Hook'' plan within three days under the operational title ''Pocket Money''.<ref name="Morocco, p. 130"/>

At precisely 09:00 (local time) on 9 May, six US Navy [[A-7 Corsair II]]s and three [[A-6 Intruder]]s from the USS ''Coral Sea'' flew into Haiphong harbor and dropped thirty-six {{convert|1,000|lb|kg|adj=on}} Mark-52 and Mark-55 naval mines into its waters. They were protected from attacks by [[Vietnam People's Air Force]] (VPAF) [[MiG]] fighter aircraft by the guided-missile cruisers {{USS|Chicago|CA-136|2}} and {{USS|Long Beach|CGN-9|2}}, with several destroyers including the guided-missile destroyer {{USS|Berkeley|DDG-15|6}} launching [[Operation Custom Tailor]] and by supporting flights of F-4 Phantoms. The reason for the precise timing of the strike became apparent when Nixon simultaneously delivered a televised speech explaining the escalation to the American people: "The only way to stop the killing is to take the weapons of war out of the hands of the international outlaws of North Vietnam.".<ref name="Morocco, p. 131">Morocco, p. 131.</ref> The mines were activated five days after their delivery to allow any vessels then in port to escape without damage.<ref name="Tilford, p. 233"/> Over the next three days other US carrier-based aircraft laid 11,000 more mines into North Vietnam's secondary harbors, blockading all maritime commerce for the country.<ref>Andrade, p. 518.</ref>

Before and during ''Pocket Money'', Nixon and Kissinger had worried about the Soviet and Chinese reaction to the escalation. Hours before Nixon's speech announcing the mining, Kissinger had delivered a letter to Soviet ambassador [[Anatoly Dobrynin]] which outlined the U.S. plan, but which also made clear Nixon's willingness to proceed with the summit.<ref>Fulghum and Maitland, pp. 170–171.</ref> The next day, Nixon shook the hand of Soviet Foreign Trade Minister [[Nikolai Patolichev]] at the [[White House]]. Although Moscow and Beijing publicly denounced the American operation, they were not willing to jeopardize their thawing relationship with the U.S. and Hanoi's requests for support and aid from its socialist allies met with only cool responses.<ref name="Morocco, p. 131"/>