The Obama administration must refocus on a key geostrategic imperative: stopping the erosion of allied confidence in American reliability. The brouhaha over last year’s decision by the United States to adhere to China’s air-defense identification zone in East China Sea obscured this key issue. The dust having since settled, it is worth revisiting the facts. At the time, the efforts to persuade Tokyo that informing China of U.S. civilian flights was an FAA (Federal Aviation Administration) decision reaffirmed the instincts of our Japanese friends that Washington could not be relied upon. No wonder that Tokyo’s new military strategy (euphemistically termed “proactive pacifism”) calls for acquisition of drones and amphibious assault vehicles.

It is time for the Obama administration to concentrate with a laser-like precision on an urgent strategic challenge: not the FAA, but PAA—perceptions of American allies. By tacitly acquiescing to China’s air defense zone, the United States deepened the pervasive perception among our Asian allies—grounded in a long history of U.S. ambivalent behavior towards its friends in the region—that it is an unreliable security patron, increasing their temptation to explore alternative security assurance options, including nuclear weapons. If Beijing moves to establish a second air defense zone over the South China Sea, this will be yet another litmus test of the U.S. reliability, and our allies will be watching Washington’s response carefully.

American allies in Asia have long memories—many of which come with a bitter nuclear aftertaste. President Park Geun-hye of South Korea will remember that her father launched a nuclear-weapons program over forty years ago, when he feared U.S. commitment to the country’s security was flagging. At the time, the U.S. credibility in the eyes of allies was damaged by the withdrawal from Vietnam and the rapprochement with China. Indeed, in July 1971 then president Park Chung-hee pointedly asked: “How long can we trust the United States?” The U.S. finally managed to stop Seoul’s nuclear pursuit by denying it access to the key nuclear equipment required to build the bomb. Roughly at the same time, Taiwan likewise launched a nuclear-weapons program, driven by concerns about its security position as a result of the new U.S. relationship with China. Here, too, Washington had to exert significant coercive efforts to impede Taipei’s ability to pursue its nuclear work and eventually to reverse its extensive clandestine efforts.

Today, as in the Cold War, U.S. allies in Asia doubt the reliability of U.S. security assurances. Calls for nuclear self-reliance long have been heard in South Korea, and are bound to get louder if the U.S. continues to hesitate to respond decisively to China’s behavior. The atomic debate is alive, if subdued, even in the nuclear-scarred Japan. Prime Minister Shinzo Abe this year is expected to press for easing of the restrictions on Japanese armed forces to engage in self-defense. He has already centralized national security decision-making by creating a first-ever National Security Council.

The U.S. has a perception problem, and must take concrete steps—declaratory, diplomatic, and military—to rectify it. First, the U.S. should confront China in the UN Security Council by rejecting Beijing’s unilateral actions and instead proposing a negotiation process to resolve the dispute. So far, the Obama administration has gotten it wrong by acknowledging that China’s action “constitutes a unilateral change to the status quo.” This statement sends a damaging signal to our allies that the United States accepts Beijing’s actions as legitimate, which further undermines Washington’s credibility in the region. To start reassuring our allies, the United States must instead communicate in words and actions that the status quo has not changed.

Washington must now do an about-face and declare that China’s actions are illegitimate and should be considered null and void under general principles of international law. American UN representative Samantha Power should quote the UN Charter in stating that China’s actions violate “international peace and security.” Secretary Kerry should separately state unequivocally that the U.S. intends to continue operating its commercial, civilian and military fleets in the East China Sea as if the air defense zone did not exist.

There is a good precedent for taking such a posture. Washington should give Beijing the same treatment as it gives North Korea: the United States has never recognized Pyongyang as a legitimate nuclear power despite its nuclear tests. Critics who will call this another instance of American flip-flopping—first acquiescing to China and now trying to be firm—should be reminded of Winston Churchill’s apt observation that “Americans will always do the right thing—after exhausting all the alternatives.” It is not yet too late to do the right thing.

No doubt, such public pronouncements will be viewed skeptically unless they are backed up by actions. The vacillation over the public “red line” on chemical weapons use in Syria has created a bad precedent. Thus, as a second step, after taking a firm public stand against China’s actions, the U.S. should propose the launching of a special mediation process to achieve a negotiated, peaceful resolution—phrasing that Beijing is sure to appreciate—of the dispute. Washington should recommend that Mohamed ElBaradei, a well-respected former International Atomic Energy Agency Director-General and a Nobel Peace Prize winner, serve as a neutral lead mediator.

Third, the United States should continue to take actions to militarily reassure its allies. Promptly sending two unarmed B-52s was a good first step. An additional option the Obama administration ought to consider is to engage in consultations with Australia about increasing our force presence on the continent from the current projection of 2,500 Marines by 2016/2017. As in the Cold War, boots on the ground are the most effective demonstration for our allies that America is truly committed to their security.

"History does not repeat itself, but it does rhyme," Mark Twain is said to have observed. As in the past, our allies are worried and uncertain about the U.S. intention to protect them. It is time to remember Churchill’s adage and take concrete steps to strengthen the relationships with our friends in Asia. Given the nuclear alternatives our friends might pursue on their own, this is well worth the investment of America’s resources.

Eugene B. Kogan is Stanton Nuclear Security Postdoctoral Fellow at Harvard Kennedy School’s Belfer Center for Science and International Affairs. He is writing a book about nuclear negotiations between the United States and its allies.