In the days after the last helicopter lifted off the United States embassy helipad, the Saigon sky fell silent and the victors got busy raising the red and gold standard of the National Liberation Front on the flag poles of foreign missions. The fortress-like American embassy alone did not have the NLF flag. Asked about the reason for the exception, an officer from Hanoi assured me with a smile: “The Americans will be back soon.” As he explained, “The Americans worry about Chinese expansionism and they know, historically, Vietnam has been the biggest barrier against Beijing’s southward drive.”

Earlier this year US Secretary of Defense Leon Panetta was granted a tantalising tour of the famed Cam Ranh Bay that figured prominently in America’s strategic imagination. This is not to suggest that the US and Vietnam are anywhere near the strategic cooperation that my Vietnamese interlocutor dreamed of in 1975, but the zigzag journey of reconciliation and rapprochement between the two adversaries remains a gripping tale. The story also offers valuable lessons in the interplay of three factors—geopolitics, nationalism, and ideology—that shaped the kaleidoscopic transformations. Vietnam’s two thousand year history of love-hate relations with its giant neighbour China, its national ambition, and the ruling Communist Party’s concern about regime maintenance might explain the tortured path towards normalisation.

At the end of the war in 1975 the Vietnamese party was flush with its historic victory, eager to rebuild the ravaged nation but worried about the signs of overt hostility from China. Its optimism about speedy restoration of ties with Washington, because of broad geopolitical considerations, may have been logical thinking but it was based on a total misunderstanding of the American policy dynamic. Despite President Jimmy Carter’s desire to restore ties with all erstwhile enemies in Asia, including China, normalisation of relations with Vietnam proved impossible. Carter did not share Vietnam’s long-range perspective and Vietnam, on its part, underestimated America’s deep psychological war wounds. While it wanted relations with Washington to balance Chinese power, Vietnam was too proud a victor to forego the spoils of war—reconstruction aid promised by the US in the Paris peace accord of 1973. After the normalisation talks collapsed in 1978, the geopolitical context underwent a dramatic shift unfavourable to Vietnam that lasted nearly two decades.

Four years after the end of the long war, Vietnam was again in a state of war on its northern and western fronts. Chinese-backed Khmer Rouge attacks on its western border in 1977–78 led to Vietnamese invasion and occupation of Cambodia. China retaliated with a punitive invasion of northern Vietnam in 1979. This began a decade-long period in which Vietnam faced economic crisis at home and isolation abroad. The pressure of the de facto alliance between the US and China and their support of the Khmer Rouge–led coalition was compounded by the loss of support from a Soviet Union undergoing perestroika. The talks on normalisation of relations with the US were bogged down by unending American demands for accounting of their POWs and missing in action (MIA) during the war. The conservatives in the administration and the military, who never forgave Vietnam for America’s national humiliation, sought to restore the country’s honour by bringing home the remains of fallen soldiers and maintaining a crippling trade embargo imposed since 1975. To emerge out of its economic troubles and diplomatic isolation, Vietnam launched its doi moi (renovation) reforms and began the withdrawal of its troops from Cambodia, which was completed in 1989.

By the time Vietnam came close to withdrawing its troops, as demanded by the US and ASEAN, and engaged in talks with them over Cambodia’s political future, the geopolitical context changed again. The Sino–Soviet rapprochement and the international isolation of Beijing following the Tiananmen massacre not only altered the external environment but also raised concerns about the regime’s security. The large protests in China, which ended in the violent suppression in Tiananmen Square, and the domino-like fall of socialist regimes in Eastern Europe that came shortly afterwards rang alarm bells in Beijing—and in Hanoi. While Vietnam sorely needed aid and trade with the West, it was wary of “peaceful evolution” and subversion of the socialist system in the name of assistance. The George H. W. Bush administration’s so-called road map for normalisation was viewed with deep suspicion. Vietnam’s top diplomat Nguyen Co Thach’s failure to obtain normalisation, despite many concessions on MIA and the withdrawal from Cambodia, led Hanoi to alter its anti-Chinese trajectory. A secret summit meeting between Chinese and Vietnamese party leaders was held in Chengdu on 4 and 5 September 1990. The ground was laid for a gradual de-escalation of China’s conflict with Vietnam and an agreement to form a coalition government in Phnom Penh under UN auspices.

With normalisation of relations with China on course, Vietnam’s main objective in seeking ties with Washington was economic cooperation. But Vietnam was still very much on guard against threats to the socialist regime. Ironically, the Democratic administration under Bill Clinton proved tougher on Vietnam than the previous Republican administration. Pressed by right-wing politicians, the Clinton administration stepped up pressure over MIA and human rights violations. Business though saw opportunities in Vietnam and its concerted lobbying forced Washington to eventually agree to soften its stance. In February 1995, America lifted its trade embargo against Vietnam, and in July came the announcement that diplomatic ties would be restored. When, finally, on 5 August 1995 (a full 30 years after the end of the war), secretary of state Warren Christopher unfurled the Stars and Stripes in the US embassy in Hanoi, Vietnam’s main concern had shifted. It was no longer as interested in a strategic alliance as it was in ways to open the economy to the world and, specifically, win favoured nation trade status.

Vietnam’s reticence in being seen as a US ally against China was evident in March 2000. Defense secretary William Cohen became the first cabinet official to visit Vietnam, but Hanoi went out of its way to announce that there was no talk of strategic ties. Even when Clinton came to Vietnam in December 2000, a secret Central Committee directive told party members to show a “cold face” to Clinton. The gap between the Communist Party and the people could not have been starker. I watched thousands of young Saigonese break through police cordons to rush towards the presidential limo shouting “Bill, Bill!” For the Party it was America coming to Canossa and recognising Vietnam rather than Vietnam seeking closer ties with America with an eye to the north. In his meeting with Clinton, secretary general Le Kha Phieu gave the president a lesson in Vietnam’s glorious history of resistance to aggressors, but did not discuss the present or the future of relations with the US. For that, Vietnam had to wait another three years and a change in the external environment.

The second Bush administration seemed to move away from the somewhat smarmy attitude the US had toward China in the wake of the EP-3 spy plane incident. Even before the tension over the spy plane, important voices in Washington expressed concern about China’s muscle flexing. One of the authors of the RAND corporation report, Zalmay Khalilzad, who would become a national security adviser, noted that the United States should bolster its overall military presence in Asia in response to rising Chinese power. It pointed out that “there is an underlying logic to cooperation between the United States and Vietnam to prevent a Chinese bid for regional hegemony.” As Washington began focusing on changing the balance in East Asia, its interest in Vietnam took on strategic significance.

Vietnam, too, was worried about China’s continuing push in the South China Sea and in the states along Vietnam’s periphery. In the June 2003 Central Committee plenum, the party surmised that the situation in East Asia was developing in an unfavourable way and efforts had to be made to develop ties with the US. As the Vietnamese told American officials, “The triangle is out of balance.” US relations with Vietnam were weak, while its ties with China had improved a great deal and China’s influence in the region had grown. This new mutual awareness led to the first-ever visit by a Vietnamese defence minister to Washington in November 2003. It was followed by the first port call by Navy ship the USS Vandergrift to Ho Chi Minh City.

The high point in the warming ties came in June 2005, when Phan Van Khai became the first Vietnamese leader to be entertained at the White House. In their joint statement George W. Bush and Khai said they “shared a vision of peace, prosperity, and security in Southeast Asia and the Asia-Pacific region, and they agreed to cooperate bilaterally and multilaterally to promote these goals.” The inclusion of the phrase “Asia-Pacific region” in the communiqué was the only public hint that the relations went beyond bilateral or even regional—Southeast Asian concerns. Khai signed an intelligence agreement with the United States allowing cooperation on staunching money laundering and engaging in intelligence sharing with Washington.

Against the backdrop of growing Chinese power and assertiveness in the South China Sea US–Vietnam relations have deepened. US Secretary of State Hillary Clinton’s visit in Hanoi during an ASEAN ministerial meeting in 2010, where she expressed US concern about Chinese behaviour in the South China Sea, marked a new level of cooperation with Vietnam. The following year, US and Vietnam entered into discussions to raise their bilateral relationship to a strategic partnership. Military ties too have grown. During the Vietnamese defence minister’s 2003 visit to Washington, it was decided that similar level exchange visits would take place every three years. Vietnamese and US defence chiefs have since exchanged four visits. Leon Panetta’s June 2012 visit drew more than the usual attention against the backdrop of deteriorating US–China relations. Panetta was given a tour of Cam Ranh Bay, where Soviet naval assets and long-range bombers were once based.

While the relationship has grown dramatically in the past decade, the interplay of three factors continues to modulate the relations. A militarily strong China poses a greater threat to Vietnam’s sovereignty than at any time in the recent past. But the Vietnamese Communist Party shares the Chinese Communist Party’s concerns about a Western threat to their system, all the while seeking Western economic cooperation to build a prosperous and powerful country.

In 1978 a Vietnamese diplomat, Luu Doanh Huynh, explained the logic behind Vietnam’s cultivation of Moscow: “In all of history we have been secure from China in only two conditions. One is when China is weak and internally divided. The other is when she has been threatened by barbarians from the north. In the present era, the Russians are our barbarians.” The same logic can be applied to Vietnam’s need to cultivate the US today—a powerful friend to deter China from being too aggressive. As Vietnamese leaders frequently remind foreigners, a country can choose its friends but not its neighbours. However enticing it might be, Vietnam would shun any military alliance with Washington that could provoke its giant neighbour’s hostility or make the Vietnamese government vulnerable to American pressure on democracy and human rights. Rapprochement between the two countries is real but so are the limits.