President Barack Obama’s historic visit to Vietnam, during which he announced the complete lifting of a long-standing U.S. ban on lethal weapons sales, culminated the process of normalization between Vietnam and the United States. In the joint statement with President Tran Dai Quang, Obama emphasized that the lifting of the ban “will ensure that Vietnam has access to the equipment it needs to defend itself and removes a lingering vestige of the Cold War.” In addition, defense cooperation measures to strengthen the Vietnamese coast guard were announced, and Obama, referencing the South China Sea issue, reiterated that “the United States will continue to fly, sail, and operate wherever international law allows, and we will support the right of all countries to do the same.”

Obama’s visit was hugely popular with the Vietnamese people, many of whom crowded the streets in Hanoi and Ho Chi Minh City to welcome him. Newspapers and the online sphere were filled with positive comments about Obama’s embrace of the local culture and food and his open and relaxed style. Photos of Obama eating bun cha and posts about his sensational speech in Hanoi have been flooding the newsfeed of millions of Vietnamese Facebook users in the past few days.

Undoubtedly the visit signals the desire of both countries to deepen cooperation and their willingness to tackle thorny issues. Taking steps to address Washington’s concerns about human rights, Hanoi will receive the Peace Corps and has granted Fulbright University Vietnam permission to operate as the country’s first nonprofit, independent university, not subject to any constraints by the central government on its curriculum. Obama’s visit will also help to further lock-in Hanoi’s commitment to the Trans-Pacific Partnership, with respect for independent labor unions arguably the most noteworthy.

While these upgrades in U.S.-Vietnam relations are apparent, Obama’s visit and the lifting of the lethal weapons sale ban need to be situated in the context of the U.S.-China-Vietnam triangle and Beijing’s assertiveness in the South China Sea. Contrary to President Obama’s  insistence that “the decision to lift the ban was not based on China or any other considerations,” but only “on our desire to complete what has been a lengthy process of moving towards normalization with Vietnam,” one can argue that concerns about China and its moves in the South China Sea loom large.

This trip is not just about the United States enlisting the support of Vietnam in order to constrain China. It is also about the United States pulling Vietnam closer to its own orbit more generally. In the short term, the visit and the lifting of the ban carry symbolic importance. First, they signal that the change in leadership after the 12th Party Congress in January will not fundamentally alter Vietnam’s foreign policy direction. While some speculated that the leadership change would bring Vietnam closer to China for ideological reasons, Vietnam’s “pivot” to the United States will continue. Obama’s visit confirms that.

Second, the trip signals that a “cooperative strategy for 21st century sea power,” will continue to emerge in the region, and it will not be easy for Beijing to apply a divide and conquer strategy. Shortly before the president’s trip, China sent three delegations to Vietnam. It is unclear what went on behind the scenes, but Chinese officials likely tried to warn Vietnam against deeper cooperation with the United States, potentially citing the risk of “peaceful evolution”—a euphemism for gradual U.S.-backed regime change. If true, the success of Obama’s trip indicates that Vietnam is not willing to yield to such pressure from the Chinese side. The recent development of Vietnam-U.S. relations might be able to convince leaders in power that “peaceful coexistence” between a one-party communist state with a democratic superpower is possible.

Besides its short-term symbolic importance, the lifting of the arms sale ban can enhance Vietnamese capacities in the long-term. Right now, Vietnam’s naval and air defense platforms were mostly purchased from Russia, which poses an obstacle to the integration of new U.S. hardware. In addition, Vietnam’s purchasing power is relatively constrained. However, in the long-term, the lifting of the ban will open the door to more advanced capabilities, helping the country to protect its status quo in the South China Sea. There could eventually be joint maritime patrols between the U.S. and Vietnamese navies, and a more robust U.S. commitment to ensure maritime security and stability in the South China Sea.

Furthermore, the lifting of the U.S. lethal weapons embargo is a crucial starting point for more robust defense cooperation. The fact that the United States allows Vietnam to buy its weapons despite remaining differences regarding human rights issues is bound to have some spillover effect in the long-term. This decision will allow both sides to build mutual trust, which will permit more far-reaching cooperation. The United States has long expressed its desire to return to Cam Ranh Bay naval base, and recently, there have been intensive talks on both sides on how to make such a return possible without unsettling China too much. Cam Ranh occupies a strategic location in the South China Sea, as it is closer to the disputed Spratly Islands than any major Chinese naval base.

To deter Beijing from continuing to change the status quo in the South China Sea and militarizing the dispute, Vietnam must cooperate with the United States. Ultimately, the greatest value of such cooperation, both bilateral and multilateral, lies in the ability to send a strong deterrence signal to China. Whether Vietnam’s deepening cooperation with the United States will pay off depends on how China perceives these signals.

One can imagine two likely scenarios. In the first, stronger U.S.-Vietnam ties and the confidence gained by Vietnam as a result of the president’s visit might help to dissuade China from taking aggressive actions against Hanoi (e.g. placing another oil rig in Vietnam’s claimed exclusive economic zone, attacking Vietnamese fishermen/coast guard, ejecting Vietnam from some of the features it occupies in the South China Sea). Another possibility is that the visit could irritate Beijing and encourage it to apply political and military pressure on Hanoi. Since China and Vietnam share a common border, troop movements near the border can be used as a military threat by Beijing at any time. A dual strategy of carrots and sticks might be used to “quarantine” U.S. influence on Vietnam. Therefore, it is recommended that Vietnamese leaders adopt a cautious stance in the aftermath of the Obama visit in order to avoid damaging relations with Beijing.

About Nhung Bui

Nhung Bui is a PhD Candidate in the Politics Department at Princeton University and a research associate at the Center for International Studies (SCIS) at the University of Social Sciences and Humanities in Ho Chi Minh City.

About Truong Minh Vu

Truong-Minh Vu is a visiting fellow at the ISEAS-Yusof Ishak Institute, Singapore and director of the Center for International Studies (SCIS) at the University of Social Sciences and Humanities in Ho Chi Minh City. He is co-editor of the book "Power Politics in Asia’s Contested Waters: Territorial Disputes in the South China Sea" (Springer, 2016).