The recent U.S. decision to upgrade Taiwan's existing fleet of F-16 fighter aircraft—taken in response to China's growing military threat to the island—has triggered a repeat of what most observers regard as a troublesome but ultimately manageable dynamic: Washington sells arms, Beijing blusters and threatens, the bilateral relationship suffers some disruption, and then everything returns to business as usual across the Taiwan Strait. But this kind of business as usual could lead to a major crisis with China.

In the existing dynamic, Washington sees itself as a stabilizer, encouraging cross-strait dialogue, cautioning both sides that it will oppose any unilateral actions that might threaten the peace and deterring Beijing by maintaining its military predominance in the Western Pacific while boosting Taipei's defense capabilities. All of this is basically done at arm's length. Washington leaves it to Beijing and Taipei to resolve their political differences through direct contact while itself avoiding any dialogue with Beijing over the cross-strait military buildup, other than to indicate a willingness to reduce U.S. military assistance to Taiwan if Taipei sees a reduced requirement as a result of a unilateral Chinese drawdown.

This "hands-off" U.S. approach has worked reasonably well for more than thirty years, despite the occasional mini-crisis, thus creating the widespread expectation that it will continue to work indefinitely into the future. The U.S.-China relationship, the argument goes, is too important for Beijing to risk serious damage to it by retaliating in any major way against U.S. arms sales, especially if Washington avoids providing Taiwan with certain advanced weapons (this time, it did not act on Taiwan's request to purchase new and more sophisticated F-16s—an apparent red line for Beijing) and does not endorse Taiwanese independence.

Moreover, proponents of the status quo assume that as long as Taiwan's political leadership welcomes greater cross-strait contact and does not seek permanent separation from the mainland, Beijing will always favor negotiation over coercion. Indeed, currently improving cross-strait contacts supposedly suggest movement toward some sort of stable long-term modus vivendi. Finally, according to this optimistic view, Washington will retain the military wherewithal to deter any Chinese resort to force, as long as Taipei is able to keep Beijing at bay long enough to let U.S. forces intervene in a conflict.

The problem with this argument is that several emerging trends cast significant doubt on its continued validity.

First, China's steady military buildup is rapidly making it impossible for Washington to resist selling far more sophisticated weapons to Taiwan of the sort that Beijing would view as unacceptable. These would likely include more advanced aircraft, warships, and possibly missiles with both defensive and offensive capabilities. Absent a major breakthrough in cross-strait relations or a highly unlikely unilateral Chinese drawdown of its direct military threat to Taiwan, such U.S. sales are virtually inevitable under current conditions.

Second, China's ability to inflict significant pain on the United States in retaliation for such arms sales to Taiwan is increasing. If China's rapid growth continues and America's severe economic problems persist over many years, it is quite possible that Beijing will reach the point where its calculation of the benefits resulting from a variety of possible severe retaliations will outweigh their presumed costs. This is especially true given the highly emotional nature of the Taiwan issue in China and its association with an increasingly assertive strand of nationalism. Such forces could compel future Chinese leaders to undertake highly dangerous actions to deter or punish future arms sales.

Third, a tension-reducing breakthrough in cross-strait relations seems highly unlikely for a very long time, if ever. Despite all the improvements of recent years in those relations, Taipei and Beijing have yet to reach any understanding that would permit a reduction in their military buildups, much less a stabilizing dialogue over the island's political status. The fault for this lies on both sides and is rooted in deep-seated mutual distrust as well as strong domestic political opposition to any unilateral conciliatory initiatives. Moreover, this impasse will become even more likely if the pro-independence political opposition wins the Taiwan presidency next year—a definite possibility.

For many U.S. observers, the only "solution" to the intensifying problem created by these factors is to keep selling arms to Taiwan, plow ever-more scarce U.S. resources into maintaining military predominance in the Western Pacific, keep providing verbal assurances to Beijing that it does not support unilateral moves by Taiwan toward independence, and continue urging Taipei and Beijing to work out their differences peacefully. But China's military buildup, its increasing economic and political leverage, and its growing nationalism suggest that a serious future crisis over arms sales will likely occur before any significant movement toward a stable modus vivendi between Beijing and Taipei emerges.

Only the United States can alter China's calculus toward Taiwan in ways that would facilitate a military drawdown and genuine movement toward a more stable cross-strait military and political relationship. It is time for Washington to consider negotiating directly with Beijing, in consultation with Taipei, a set of mutual assurances regarding Chinese force levels and deployments, on the one hand, and major U.S. arms sales and defense assistance to Taiwan, on the other hand—linked to the eventual opening of a cross-strait political dialogue on the status of Taiwan. Success in such an effort would be difficult but not impossible. It would require political courage, diplomatic acumen, and a recognition that the current U.S. approach to Taiwan is probably unsustainable and could prove disastrous.

Michael D. Swaine is a senior associate at the Carnegie Endowment for International Peace and author of the new book, America's Challenge: Engaging a Rising China in the Twenty-First Century.