The U.S. is browbeating allies to back its ever more confrontational policies toward the People’s Republic of China. For good reason, Washington doesn’t want to go to war alone.

America is more powerful, but its armed forces face the tyranny of distance. It costs the U.S. more to project power than for China to deter the exercise of power. Moreover, Washington still wants to run the world—protect rich Europeans, remake failed Middle Eastern societies, engage in almost endless nation-building in Central Asia, and do whatever else catches the fancy of one U.S. policymaker or another. In contrast, Beijing concentrates on what matters most, its own region, and has not wasted thousands of lives and trillions of dollars on decades of foolish war-making around the globe.

So Washington is trying to round up volunteers for its anti-China posse. To Americans, the project looks like an easy sell. Who likes the ChiComs? Antagonism toward Beijing is widespread. However, winning support for warring against a fast-rising great power likely to hit superpower status is not so simple.

Europeans are increasingly willing to criticize and even sanction Beijing over human rights, but few of them want to defend themselves, preferring to leave that task to Washington. Even less do they want to fight for other nations. Consider Germany, which after a spirited debate within the government decided to dispatch one frigate to roam Asian-Pacific waters, to spite the PRC, while proposing a visit to Shanghai to conciliate the PRC.

Asia is simultaneously an easier and harder case. It is easier because what happens in Asia obviously matters more to countries located in Asia. It is harder because what happens in Asia obviously matters more to countries located in Asia. Even the RAND Corporation, a reliable adjunct to the military-industrial complex, warned that aid for America is not certain.

Earlier this year RAND’s Bonny Lin told Congress:

Although U.S. allies and partners might more readily provide diplomatic assistance (in terms of criticism of PRC use of force) if China attacks Taiwan, there is likely to be variability in their willingness to provide military assistance to Taiwan, and the United States will likely have to shoulder the majority of the military aid to the island. Even some of the closest U.S. allies, such as Japan and Australia, may face constraints that limit their ability to contribute.

Tokyo is the ally whose support Washington most desires in any conflict with the PRC. Japan has the best Asian military outside of China, is close geographically to Taiwan, has cooperated with the U.S. armed forces for decades, and is an existing treaty partner.

The Biden administration used the recent Suga-Biden summit to press for a Japanese commitment to back Washington in aiding Taipei against China if the latter attacked the island. Taiwan was mentioned in the joint statement, a first. Prime Minister Yoshihide Suga said the leaders had agreed “to oppose any attempts to change the status quo by force of coercion.” But then, under domestic fire, he explained that Japanese forces would not be deployed to defend Taiwan and that the official statement “does not presuppose military involvement at all.” Deputy Prime Minister Taro Aso added to the muddle. He said that in the case of a “major problem” with Taiwan “then Japan and the U.S. must defend Taiwan together.” Other officials dismissed his comments as personal and he said any incidents involving the island should be resolved with diplomacy.

Confused? As my colleague Ted Galen Carpenter put it: “U.S. and Japanese leaders are busily making murky, often contradictory, policy statements about Taiwan. In the process, they have infuriated the People’s Republic of China (PRC) and increased the risks of a miscalculation that could culminate in a catastrophic war. Greater clarity—and far greater prudence—is urgently needed.”

The first problem is the widespread assumption that Washington should, indeed, must defend Taiwan. Although the Taiwanese deserve to decide on their own future, that does not mean it is in America’s interest to go to war for the island state. Nor can Americans assume that Beijing would back down in the face of U.S. threats. The issue matters much more to China, which consequently is willing to risk and sacrifice far more. The Civil War provides a terrifying lesson: Both the North and South expected the other side to give way and were proved wrong. Some 750,000 Americans died, proportionally the equivalent of eight million today.

If Beijing ignores U.S. warnings and uses coercion against Taiwan, are Americans prepared for a real war with a nuclear-armed power? This would not be like beating up on Saddam Hussein’s hapless army or fighting insurgents armed with AK-47s in Afghanistan. Imagine an aircraft carrier or two joining the Titanic at ocean’s bottom, with thousands of sailors killed. Imagine the U.S. without air superiority, losing multiple aircraft. Imagine missiles striking U.S. bases in Guam, Okinawa, and South Korea. Imagine nuclear-tipped missiles crossing the Pacific, targeting the American homeland. Hopefully such a nightmare never occurs.

But anyone who claims to know how a Sino-American war would play out is lying.

No matter what the Biden administration says, there is no guarantee that its successors will take the same position. Japan could commit itself to war and find itself facing a vengeful China alone. Indeed, the lack of a treaty makes it easier for a future president to step back from the brink, especially if the PRC continues to close the military gap. The pressure for retreat could grow exponentially if a heretofore uninvolved American public suddenly discovered that an administration planned to drag them into a possible nuclear war half the world away to protect a place few could locate on a map. Even more so, the policy of “strategic ambiguity” allows a president to justify inaction by the lack of any public commitment to Taiwan. Credibility wouldn’t officially be on the line.

Nor are Japanese promises today enforceable tomorrow. Only a few years ago did Tokyo change its defense guidelines to allow it to come to the aid of American forces under attack—even though Washington had spent a half century promising to protect Japan. Expanded rearmament remains a controversial topic. Despite enjoying a strong parliamentary majority, the previous prime minister, Shinzo Abe, was unable to revise the famed “peace constitution.” Joining a war in which Japan was not attacked would be highly controversial and perhaps politically impossible.

Although an assault on Taiwan would create a more threatening regional security environment, it would not presage similar action against Japan. Taiwan always was a special case, indisputably Chinese territory seized by the Japanese Empire in war more than a century ago. Although the PRC claims the Senkaku/​Diaoyu Islands, it has shown no interest in seizing Japan, which could create a much larger military capable of deterring any threat to Japan’s main islands.

Staying out of a China-Taiwan confrontation might be dangerous for Tokyo, but not as dangerous as joining. Supporting America against China would increase the former’s likelihood of victory, but even success would be dearly bought. Although the U.S. has Pacific possessions within easy range of Chinese weapons, the American homeland is well distant. In contrast, Japan is close and would be an inevitable military target. Any bases used by Japanese or American forces would be valid targets, and the PRC might not be restrained in deciding what and who to bomb. Would Japanese citizens, so consistently skeptical of rearmament, supinely accept their government’s decision to bring war into their homes on behalf of a foreign land?

Moreover, any conflict likely would not end after a Chinese defeat. Rather, Beijing would begin rearming for the next round. A defeat so close to the mainland by foreign powers would put the PRC in greater danger than before. Failure might result in the ouster of the government responsible for such a national debacle. However, the prospect of other nations using Taiwan, which is barely 100 miles offshore, to contain China would be intolerable. Like Germany after losing World War I, Beijing could be counted on to seek vindication and revenge—early and often.

Tokyo might be more secure ignoring Taiwan while cooperating with other regional states, such as the Philippines, Indonesia, Vietnam, and Australia. All have reason to worry about Chinese designs, including contested territorial claims. None, however, face obvious threats to their independence. Moreover, Beijing’s interest in them remains far less than in Taiwan. Creating such a multilateral counterweight to the PRC would help constrain Chinese ambitions without challenging Beijing over what is a much more important issue for them.

This doesn’t mean that nothing should be done for Taiwan. Japan could work with Washington to help organize a multilateral warning to China on economic and diplomatic sanctions that would be triggered by aggression against Taiwan. Few nations are prepared to join a war against the PRC in Asia. Many more might be willing to accept the economic cost of seeking to prevent a conflict which would not only victimize Taiwan but necessarily unsettle markets and commerce worldwide.

America would be better off if Japan and other allies realistically assessed their interests rather than over-promised to satisfy Washington. The U.S. government’s primary responsibility is to its own people, too, which would warrant avoiding a conflict with China, especially since the U.S. could very well end up fighting alone. Washington might get the answer that it wants pressuring Japan today, but it could be surprised when Tokyo repudiates its ill-made promise at the moment of crisis.