Commentary: Time for Washington to self-question its Asia-Pacific policy

In the countdown to a farewell to the White House and prior to perhaps his last visit to Asia as a sitting U.S. president, Barack Obama should reflect upon his policies that failed to contribute to regional peace and stability.

Obama starts a weeklong trip to Vietnam and Japan on Sunday.

Picking Vietnam, a former bitter foe that is now seeking to enhance ties with Washington, and Japan, a traditional ally, as his destinations, Obama aims to consolidate the "Asia-Pacific rebalance" and the Trans-Pacific Partnership (TPP) that would cement an economic alliance between the United States and 11 other Pacific-rim countries including Vietnam and Japan.

In Obama's first visit to Vietnam, the South China Sea issue is expected to be one of the topics high on his agenda.

The issue related to the South China Sea, one of the world's most important trade routes, is mainly about maritime territorial disputes between China and some other Asian countries, which should be solved through negotiations under the Declaration on the Conduct of Parties in the South China Sea.

However, tensions in the South China Sea have escalated in recent years as Washington repeatedly sent military aircraft and vessels to the region to carry out missions of what it called "freedom of navigation," and held joint military exercises with some claimants.

The U.S. behavior has made some countries more assertive and fueled their delusions to continue to exploit illegal interests on South China Sea islands and reefs.

For instance, the Philippine government led by outgoing President Benigno Aquino, despite criticism from the international community, unilaterally initiated an invalid arbitration case against China over the maritime territorial disputes in 2013.

Another topic that Obama's Vietnam visit will touch upon is whether to lift the arms embargo on Vietnam, which was partially relaxed in 2014.

It is welcome that Vietnam improves its ties with any other country including the United States. However, such rapprochement should not be used by the United States as a tool to threaten or even damage the strategic interests of a third country.

On the other hand, Obama, during his Asia visit, will endeavor to push through the TPP, which he is also trying to sell it at home as ratification by Congress remains in doubt in the 2016 election year.

The TPP, which covers nearly 40 percent of the global economy, is one of the paths toward establishing a free trade zone in the Asia-Pacific.

The accord is considered by the Obama administration as one of its achievements to intensify the U.S. engagement with a fast-growing region. But it should not become a political tool for Washington to make rules in Asia, as global trade rules are not determinable by a single country -- by neither China nor the United States alone -- and should rather be established by the international community.

Obama will also visit the atomic-bombed Japanese city of Hiroshima, a symbolic move showing his efforts to build a nuclear-free world, which is considered an important piece of his foreign policy legacies.

Some legacies may seem positive, at least in the short term. But others are much bitter. The legacies that can be tested by history are those that are bequeathed out of cooperation instead of containment and that are conducive to peace and development in the region and the world. Endi