As it adjusts its defense strategy to focus on deterrence, the US should refrain from violating international laws

US military strategy alternates between periods of expansion and contraction. These used to last for more than 20 years each, but their duration has now shrunk to half that. The defense strategy document, "Sustaining US Global Leadership: Priorities for 21st Century Defense", which was released on Jan 5, ushers in a new round of strategic military contraction.

The latest contraction has resulted in part from over-expansion. Over the past decade, the US' defense spending has surged from $280 billion in 2001 to $710 billion in 2011. The Iraq War lasted for nearly nine years and cost at least $700 billion in direct expenditure, although its true cost is estimated to be near $3 trillion. This expansion not only resulted in the deaths of 4,500 US soldiers and hundreds of thousands of Iraqi soldiers and civilians it also had a severe impact on the US economy.

The White House's 2011 budget plan shows the country's federal deficit takes up some 40 percent of its budget. No wonder the Pentagon, which makes up about 20 percent of the federal budget, needs to cut its spending.

The latest defense strategy, which plans to cut military spending over the next 10 years by about $487 billion, is just the first step toward further budget reductions. The Pentagon will have further spending cuts next year should bipartisan differences refuse to die, and the country's military spending will decline to around $500 billion annually on average.

Although the US will maintain its military superiority, the defense budget reduction will undermine the US' military capability, whether it chooses to admit it or not.

Compared with its military spending 10 years ago, which dwarfed that of the next 20 countries combined, the US defense budget is now just larger than the next 10 countries combined, and it might well be equivalent to only the next five countries combined in another decade.

In a rare presidential appearance at the Pentagon, Obama declared the US will continue to operate 11 aircraft carriers, but should he serve a second term it is likely that he will retire some of the carriers. In this case, the US would witness not only the end of its economic hegemony but also its global military dominance.

According to the new strategy, the US armed forces will rebalance toward the Asia-Pacific region, continue to fight terrorism and uphold its commitments to its allies and partner countries in the Middle East, reduce its military presence in Europe and develop "low-cost" and "small-footprint" approaches to achieve security objectives in Africa and Latin America.

But implementation of the new strategy will not help the US achieve these goals. The global contraction and Asia-focused strategy simply show its attempt to focus on deterrence, which will neither be effective in curbing terrorism and nuclear proliferation, nor in restraining the rise of emerging powers.

And despite refocusing its defense policy on Asia, its deterrence in the region will remain more or less the same. So far the US military has an unmatched ability to carry out global missions, nose out any potential large-scale armed conflicts and efficiently adjust the distribution of its military resources to confront any threats that come along. Hence, the Asia-focused defense policy does not necessarily mean the Asia-Pacific region is under more threat from the US than other regions.

Given the US' ability to respond to a full range of contingencies worldwide, its pressure on China will not be significantly bigger than before. More importantly, as long as it abides by international rules, the US cannot contain China's rise, when China conforms to the rule-based international order.

But the question remains whether the US will follow international rules, as it has so far failed to do with regard to Taiwan. It continually tries to intervene in China's internal affairs and persists in putting its national interests above international laws. No matter how its defense plan is adjusted, the US should be aware of the self-defeating consequences of its actions if it continues to do so.

The author is a professor and director of the Center for American Studies at Fudan University in Shanghai.