Bill Clinton was also the American president that decided to lift the 1975 trade embargo on Vietnam in 1994 and to normalize diplomatic ties with Hanoi a year later.

Since then, US-Vietnam relations have remarkably progressed, transforming into a strong, comprehensive partnership.

In Hanoi's diplomatic vocabulary, the “comprehensive partnership“it established with the US in 2013 is the lowest level of partnership it has with its key partners. It ranks behind Vietnam's “strategic partnerships” with countries, e.g. Japan (2006), India (2007), Spain (2009), Great Britain (2010) and Germany (2011), “strategic cooperative partnership” with South Korea (2009), “comprehensive strategic partnership” with Russia (2012) and “comprehensive strategic cooperative partnership” with China (2009).

However, in terms of substance, perhaps with the exception of its relations with China, its communist neighbor, Vietnam's partnership with the US is more comprehensive and strategic than the partnerships it has already agreed with all other countries.

According to data from Vietnam's General Statistics Office, the two-way trade between Vietnam and the US rose from merely $200 million in 1995 to $43.5 billion in 2015.

Whilst it is still trailing far behind Vietnam-China bilateral trade ($66.3 billion), with its export to the US worth US$ 33.5 billion, the US is now Vietnam's biggest market leading the EU ($30.9 billion), ASEAN ($18.3 billion), China ($17 billion), Japan ($14.1 billion) and South Korea ($9 billion).

Vietnam is part of the 12-member Trans-Pacific Partnership (TPP), a US-led trade agreement signed on Feb. 4, 2016. With the TPP in place, according to an estimate by the American Chamber of Commerce in Vietnam, US-Vietnam trade is expected to reach $57 billion by 2020.

One of the first deals signed on the first day of the Obama visit was an $11.3 billion order for 100 Boeing planes by VietJet, Vietnam's low-cost airline.

Their political and diplomatic ties have also considerably strengthened. In July 2015, the General Secretary of the Communist Party of Vietnam (PCV) Nguyen Phu Trong visited the US, the first by a PCV chief. Trong was warmly received by President Obama in the Oval Office, an honor only reserved for heads of government or state.

During Trong's unprecedented visit, among other key agreements, both sides agreed on two issues, which are of both symbolic and substantive significance.

The first is their agreement to pursue “a deepened, sustained, and substantive relationship on the basis of respect for [] each other's political systems, independence, sovereignty and territorial integrity.” This means the US accepts and respects Vietnam's one-party system and such a recognition is extremely important for Hanoi because the PCV's ideological conservatives strongly suspected that the US wanted to overturn Vietnam's socialist regime through the so-called “peaceful evolution.”

The second, which can be seen as a result of the first, is Vietnam's agreement to allow the US to establish a Fulbright University in Ho Chi Minh City. This was unthinkable a few years ago because at least until 2009, the CPV hierarchy was still very mistrustful of US education cooperation programs. A 2009 decree by the by the VCP Propaganda Department regarded them as a means used by the US to transform Vietnam into a western multi-party country.

All of these indicate how far the two one-time battlefield enemies have advanced their cooperation in the political and diplomatic field. Together with this, their defense relations have bolstered.

In 2011, Washington and Hanoi signed a Memorandum of Understanding for Advancing Bilateral Defense Cooperation, which outlined five key areas of cooperation namely high-level dialogue, maritime security, search and rescue, humanitarian assistance and disaster relief, and peacekeeping. In 2015, they further expanded and deepened their defense cooperation by agreeing a Joint Vision Statement on Defense Relations.

The China factor

Most significantly, Washington and Hanoi have increasingly shared common strategic interests on approaches to many key regional issues, especially in the maritime domain.

For instance, in the Joint Vision Statement adopted during Nguyen Phu Trong's American trip, both countries expressed their concern “about recent developments in the South China Sea that have increased tensions, eroded trust, and threatened to undermine peace, security, and stability” and supported “the peaceful resolution of disputes in conformity with international law, including as reflected in the United Nations Convention on the Law of the Sea.”

The pace and the extent that Washington and Hanoi have reached to each other and advanced their cooperation are remarkable, especially if taking into account the fact that the two former war foes remain virtually on the opposite side of the continuum, in terms of their political philosophy and political systems.

China's increasing assertiveness in the South China Sea is the defining factor behind this intensification of relations.

Though they did not explicitly mention China in their Joint Vision Statement, by expressing their concern about “recent developments in the South China Sea” and calling for a “peaceful solution of disputes” in this sea as per international law, both Washington and Hanoi are aimed at Beijing.

The South China Sea or in the Vietnamese, the East Sea (Bien ong) and Beijing's posturing in this sea will feature prominently in President Obama's discussions with Vietnam's leaders. He is scheduled to meet the nation's quartet of power namely party chief, state president, prime minister and legislature chair during the visit.

As it has become increasingly wary of China's behavior and ambition, especially the latter's growing aggressiveness in the South China Sea, among other key strategic and military calculations, the Vietnamese leadership has sought to build up the country's military capabilities.

Until now, Russia is Vietnam's the biggest provider of military weapons, equipment and technology. Yet, with its effort to modernize Vietnam's military capabilities, Hanoi has, for years, strongly called the American government to lift its arms embargo, in force since 1984.

In 2014, the US eased this sanction by lifting a ban on maritime defense items.

The talking point before the Obama trip is whether Obama should completely end this longstanding embargo.

Some American officials and human rights groups opposed such a move, arguing that scrapping it completely would be unwise and premature due to Hanoi's human rights abuses.

A major obstacle removed

Vietnam's poor human rights record has been a major, longstanding issue, significantly hindering the two countries from deepening their bilateral relations.

It is a reason behind President Obama's delayed trip to Vietnam. Since becoming president, and with his rebalancing to Asia strategy, he has made nine trips to Asia. During those trips, he has already been to seven ASEAN countries, with two visits to Indonesia (2010, 2011), Myanmar (2012, 2014), Malaysia (2014, 2015), Philippines (2014, 2015).

Nearly two weeks before the Obama visit, Tom Malinowski, US Assistant Secretary of State for Democracy, Human Rights and Labor, arrived in Vietnam to urge Hanoi “to release political prisoners without condition and encourage further reforms that will help to make Vietnam's laws consistent with its international human rights obligations.”

The communist regime, who has ruled Vietnam since 1945 in the North and 1975 in the South, is often criticized by the US and international rights organisations for its human rights violations. Several bloggers, rights activists and political dissidents are still held or jailed.

Recently, Vietnamese police violently disrupted rallies against the government's handling of a massive fish die-off. Vietnamese authorities also prevented many independent candidates from running for the one-party country's rubber-stamp legislature on the eve on the Obama trip.

However, just three days before his trip, the Vietnamese government granted an early release to Fr. Thaddeus Nguyen Van Ly, a Catholic priest and one of Vietnam's prominent dissidents and longest serving prisoners of conscience.

This gesture, coupled with other assurances and commitments from Hanoi to make additional progress on human rights and open up political space might influence President Obama's decision to completely remove the ban.

One of many other important decisions reached by both sides on the first day of the visit is Vietnam's agreeing to allow the US Peace Corps to operate in the country for the first time. Given Hanoi's longstanding mistrust of the program, this is a symbolically significant development.

However, overall, the strategic calculations are the defining factor behind Obama's historic decision to abolish the arms ban. They prevail over his human rights considerations.

At the conference, he said “the decision to lift the ban was not based on China or any other considerations, it's based on our desire to complete what has been a lengthy process of moving towards normalization with Vietnam.” Yet, by stating that US is fully removing the ban to allow the latter “access to the equipment it needs to defend itself,” implicitly he referred to China. Indeed, the their genuine concern about China and its actions in the South China Sea is the real reason behind Washington and Hanoi's recent efforts to deepen their bilateral cooperation.

Some rights groups may be disappointed about his decision. It is understandable given its significance of the decision. Not everyone supported Bill Clinton's decision to establish diplomatic ties with Hanoi in 1995. Yet, that move, which the former president regarded as one of the most important achievements of his presidency, opened a new and successful phase in US-Vietnam relations.

Obama's decision today will pave the way for greater cooperation between the former foes. It raises the US-Vietnam relationship to a higher level.

Whilst it is unsure whether Hanoi and Washington will give their burgeoning relationship a new terminology, it now looks like a comprehensive strategic cooperative partnership. It is probably even more comprehensive, strategic and cooperative than Vietnam's partnership with its communist neighbor.

Xuan Loc Doan is a research fellow at the Global Policy Institute. He completed a PhD in International Relations at Aston University, UK in 2013. His areas of interest and research include Vietnam's domestic and foreign policy, ASEAN's relations with major powers, and international politics in the Asia-Pacific region.

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