Illustration: Liu Rui/GT

The last couple of years have witnessed growing animosity between China and the Philippines, while China's relations with Vietnam, another major claimant to the South China Sea islands, remain relatively peaceful. Tensions between China and Vietnam have not escalated, and Vietnam has not shown much eagerness to draw close to the US. However, Vietnam still plays a significant role in the game between China and the US.

In fact, considering the structure and complexity of the contradictions between China and Vietnam, the two might face an even graver situation than that between China and the Philippines.

Among all the claimants, Vietnam claims the widest territory, almost the entire South China Sea. But Vietnam has long been wary of its northern neighbor. Historically, Vietnam was a vassal state of China for a millennium. In addition to this, the 1979 war with China still sticks in Vietnam's craw.

After the rapprochement between Vietnam and the US in 1995, their relationship is on the rise. Although the Vietnam War was calamitous for the nation, it seems that Vietnam does not bear a grudge against its former opponent.

Geopolitical considerations prevail over the pain of war. Located relatively far from Vietnam,Washington neither has a territorial dispute nor poses an imminent threat to the country's interests.

Washington's Vietnam policy has almost gained bipartisan support. Since 1995, two US presidents, Bill Clinton and George W. Bush, have paid visits to Vietnam. And regardless of who is in the White House, Vietnamese leaders are welcomed as honored guests.

In 2010, then US secretary of state Hillary Clinton declared in Hanoi that the US has a "national interest" in the South China Sea. And both countries signed an unprecedented US-Vietnam Civil Nuclear Cooperation Agreement in October 2013. Their bilateral relationship, as these events show, is in a steady process of development.

But it seems Vietnam will not be tamed as the Philippines has been. Compared with the US, Vietnam is also more dependent on China in terms of economic development. Although the US has become Vietnam's biggest export market, China remains Vietnam's biggest import market. Without China, Vietnam's economy may suffer major blows.

And there is an unbreakable barrier between the ruling Communist Party of Vietnam and Washington - a divergence in political regime and ideology.

Although the US is always a realist whose actions are based on its national interests, it never loses its innate enthusiasm for promoting Western democracy and advocating Western values such as human rights and freedom. These actions would jeopardize the governance of Vietnam's ruling party.

This dilemma between Hanoi and Washington will probably turn into a long-standing issue.

Vietnam's ruling party will hold on to its ruling position because of its success in developing the national economy. But meanwhile, subjects such as democracy and human rights will not be wiped off Washington's diplomatic agenda. The game will last a long time.

It is this dilemma that will urge Vietnam to reexamine its relationship with China and see Beijing as a valuable friend. Both are now in a similar situation, where they face the same challenges imposed by the US-led West.

These elements will turn Vietnam into a "two-faced" nation. It embraces the US when it encounters territorial disputes and geopolitical games with its neighbors. But it will give Washington the cold shoulder when the issues of political regime and ideology gain the upper hand. Its attitude toward China will be the reverse.

In the long term, Vietnam's foreign policy will be made under the cover of this "two-faced" approach. It will neither pledge allegiance to Washington as an ally, nor will it constantly maintain a "brotherhood" with China.

The author is an associate research fellow at the Institute of International Relations, Shanghai Academy of Social Sciences. opinion@globaltimes.com.cn