Zhao Minghao, research fellow with the Charhar Institute and adjunct fellow with the Center for International and Strategic Studies, Peking University

China has witnessed fruitful achievements in its diplomatic endeavors with a series of positive initiatives during the past year.

At the same time however, the US has encountered some setbacks in its "pivot to Asia" strategy.

For example, it has witnessed twists and turns in the Trans-Pacific Partnership (TPP) negotiation process, divergences among its foreign policy makers, costly military expenses and declining credibility in the Asia-Pacific region.

Therefore, how to mold a multilateral alliance and security partnership in a new strategic scenario is a critical challenge for Washington.

Martin Dempsey, chairman of the Joint Chiefs of Staff of the US, breaks the challenges and threats the US military must respond to into a "Two, Two, Two and One" construct.

According to him, there are two heavyweights in Russia and China, two middleweights in Iran and North Korea, two networks in terms of Al Qaeda and its affiliates, and then one new domain, which is cyber.

China ranks highly in this hierarchy of threats.

Apart from economic considerations, Beijing's maritime power is also growing.

For instance, its antisubmarine, air defense and missile-launching capacities have greatly been developed. It seems that the China-US contention for sea power is increasingly pronounced.

Therefore, the White House has made three major adjustments to its policies for Asia, in particular based on the regulation of its Asian alliance system.

Washington is making better preparation for any military conflict and revising its military plans with a view to boosting its maritime security power.

It has been sparing no effort to embolden the Philippines and Vietnam to hedge Beijing from the perspective of international laws.

It was with the hiring of an experienced US law firm that Manila submitted its disputes with Beijing over the South China Sea to the United Nations Convention on the Law of the Sea arbitration in January 2013.

In parallel, the US is taking advantage of Tokyo to enhance its military deployment and gain more chips to encircle China.

The US needs Tokyo to offer paramilitary equipment to certain countries and help them improve their maritime security strength.

And Japan's military cooperation with Australia is also worth noting in this regard.

In the "rebalancing to Asia" policy, the Obama administration is now focusing more on achieving near-term goals including the TPP, instead of setting broad visions. It urgently needs to integrate its allies and security partners and to develop new security networks as well.

Liu Feng, associate professor with the Zhou Enlai School of Government, Nankai University

The US-led alliance has developed into a hierarchical system in which bigger and more powerful countries provide protection for smaller and weaker states, in an attempt to garner the latter's endorsement and compliance.

Despite the fact that China has been the largest trading partner of most US allies for the past two decades, these countries still depend on Washington politically and diplomatically, which is a tenacious convention.

Recently a new term, "tributary system," has been applied to the US-centered alliance. Japanese Prime Minister Shinzo Abe and South Korean President Park Geun-hye first paid a visit to the US after they assumed office and put US-related issues top on the agenda in their diplomatic affairs, so as to win the recognition of the White House for their ruling status and its commitment to their security guarantee.

It is, thereby, fair to say that the US can influence the legal process of the government of its allies to some extent. In particular, when China's rise is viewed as a threat to Washington's dominant position in East Asia, the US will definitely remobilize its Asian allies to contain it. The range of adjustments in Washington's Asia policy has brought about major changes to China's peripheral environment, prompting China to adopt new foreign policies.

Beijing used to be relatively passive and give foremost priority to economic development. Now it attaches equal importance to economy and security given certain saber-rattling neighbors.

Beijing has already established the Air Defense Identification Zone in the East China Sea, and in the future it needs to carry out more tests when necessary.