By Zhu Feng
BEIJING - EVER since US President Barack Obama decided to begin withdrawing American troops from Afghanistan, global interest in what role (if any) China will play in determining that war-ravaged country's future has grown dramatically.
After all, China is not merely a neighbor of Afghanistan, but the world's most important rising power - indeed, a 'world power,' as Mike Mullen, Chairman of the US Joint Chiefs of Staff proclaimed in Beijing this past June.
If China proves itself willing to help shore up Afghan President Hamid Karzai's administration, it will not seek to gain any immediate advantage from the withdrawal of US forces.
But, despite the billions of dollars China has invested in developing Afghanistan's natural resources, it is hard to see it undertaking a policy of broader and proactive engagement there.
One reason why China is wary of assuming a bigger role in Afghanistan, despite the country's undoubted importance for regional stability, is that America's war there has been controversial in China from the outset.
Chinese nationalists believe that the war was undertaken by the US partly in order to place its military near one of China's most sensitive borders.
Moreover, to supply its Afghan forces, the US deepened its military footprint in Central Asia by renting the Manas Air Base in Kyrgyzstan, which also shares a border with China.
In the eyes of Chinese nationalists, these efforts were all the part of an American conspiracy to encircle China.
Thus, Chinese nationalists can't wait to see the back of America's Afghan military presence.
For Chinese strategic realists, any support for America's efforts to help end the Afghan insurgency should be part of a broader China-US bargain.
China might agree not to undermine America as it withdraws only if the US agrees to rethink its arms sales to Taiwan, or to pull back from its commitment to support Japan's claims to the Diaoyu/Senkaku islands, the ownership of which China disputes.
Obviously, such deals will be unwelcome in the US.
Given that neither Chinese foreign-policy camp believes that it will get what it wants out of cooperating with the US, both simply want America's withdrawal to happen as soon as possible, without concern for what Afghanistan will look like afterwards.
For both camps, only great-power politics matters for China's national security, and if diplomacy cannot influence the balance of power, there is little reason to engage with an issue.
For Chinese liberals, Afghanistan is fraught with ethnic threats. By recklessly denying China's request to extradite Uighur extremists to China for trial, the US showed scant regard for an issue of paramount importance - the threat posed to China?s hard-won unity by separatists.
Muslim Uighurs from Xinjiang province were captured in Taliban training campus and jailed at Guantanamo Bay with other international terrorists from 2002 through 2009.
China thought their extradition necessary to undercutting international sympathy for Uighur independence seekers.
But the US worried about the potential for human-rights abuses in China and rejected the Uighurs' extradition.
Indeed, former President George W. Bush welcomed Rebiya Kadeer, a leader of the exiled Uighur independence movement, to the White House, embittering many Chinese.
And given that the Uighur bastion of Xinjiang is close to China's borders with Afghanistan and Pakistan, the US was unwise to raise Chinese hackles in this way.
Of course, a stable, orderly, and secular Afghanistan serves China's interests as much as it benefits the rest of the world.
Yet few Chinese are willing to confess that the US-led Afghanistan war, which removed the Taliban and Al Qaeda from their dominant roles in the country, improved China's domestic security. That refusal is clearly the result of the 'structural' ambivalence that now exists between the US and China.
The extent to which China will engage Afghanistan positively will depend in large part on whether China rids itself of the prevailing zero-sum mindset and facilitates America's military withdrawal by doing what it can to stabilise the country.
China can help by stiffening the resolve of Pakistan's military to move more aggressively to contain Taliban extremists on its territory; open border regions to help resupply Nato forces in Afghanistan; and invest in the country's infrastructure.
Indeed, China's relations with Pakistan have assumed greater importance recently, owing to the tensions that now exist between Pakistan and the US.
The Obama administration's challenge nowadays is to calibrate its recent suspension of some military aid to Pakistan in order to maximise its leverage without pushing the government even closer to the extremists.
By working with the US on Pakistan, China can help secure its own interest in a strong Pakistani campaign against the militants on its territory.
Regardless of the Bush-era disputes with the US over the Uighur prisoners at Guant?namo, China is in a better position to tell its 'all-weather' friends in Islamabad that stabilising Afghanistan is not only an American objective, but a significant Chinese goal as well.
China's cooperation may not be essential to defeating Al Qaeda and other militants in Afghanistan, but it will be if lasting peace and stability is to be realised.
Chinese and US interests in Afghanistan are unlikely ever to be perfectly aligned, but the two sides can and must learn to cooperate for their own benefit, and that of the region.
The challenge for China is to exert its power and influence in a way that harmonises with the US, despite widespread displeasure among Chinese at America's position on a variety of issues, from Taiwan to the East and South China seas.
Zhu Feng is Deputy Director of the Center for International & Strategic Studies, Peking University.