International law is having a bad couple of decades. Militarily, the 1990s were a disaster for the old-fashioned notions of state sovereignty and the comity of nations. NATO waged an undeclared war against Yugoslavia without UN permission; the United States sent soldiers into sovereign Haiti and anarchic Somalia; and the perennial problem of Taiwan was postponed midway through the Clinton presidency by carrier diplomacy. In the humanitarian department, Rwanda was left hung out to dry, every safeguard set up by international law abandoned and ignored. The biggest bamboozle in diplomatic history took place in the UN itself, where the international community allowed Russia to seamlessly inhabit the seat given up by the defunct Soviet Union, based on the idea that opening that particular can of worms served no one’s interests.

The opening years of the 21st century have not been kind to international law, either. What is happening in Darfur is and has been expressly labeled genocide, and yet the world body set up to prevent it from ever happening again continues to dither. The untenable half-sovereignty of Iraq between the wars created a bizarre zone of partially-enforced international law, benefiting the Kurds but permitting Saddam’s government to flaunt standing Security Council resolutions one after the next. The result was a war that adhered to the spirit of international law but not the letter of it, because the Security Council itself was driven by France and Russia to reject the use of any coercive enforcement of resolution 1441. After the murder in Baghdad of one of international law’s best, Sergio de Mello, the United Nations threw up its hands completely.

Then there is the little matter of nuclear proliferation. The great powers agree that what happened in Pakistan and India cannot be allowed to happen in Iran. But it did happen in Pakistan and India, and the American reaction has, by necessity, been to cozy up to the Indian program and hold it close. Meanwhile a fresh limbo is thrown up around Pakistan, whose nuclear program is meant for the sort of house arrest already penning in nuclear godfather A.Q. Khan. And Iran, not to be trusted like India, is given no quarter.

MANY OF THESE OUTCOMES are just as well, and some of them are to be preferred over what would have happened had international law ruled with an iron first. But the price of global policy entrepreneurship has been an unprecedented weakening of the legitimacy of international law. The Nuclear Nonproliferation Treaty (NPT) is a dead letter; nuclear aspirants are dealt with ad hoc, on a messy and inefficient case-by-case basis. Iraq has still not been renormalized in the international system, because the people of Iraq have more pressing concerns on their mind — such as the desire of neighboring states for Iraq to be kept in yet another limbo.

Across the board, on all the major issues of the day, international consensus has disappeared. Sometimes even individual crises and cases cannot meet the basic standard of unity required of the planet by the post-World War II international order. The case of Iran is as close to that unity as we have come since the first Gulf War. But the dance of doom in which we are presently engaged over a nuclear Tehran illustrates how unpopular the status quo has become — even this status quo, which is brimming with contradictions and lacunae.

HOW BAD IS IT? The experts, as is their wont, differ — we even lack consensus on how much consensus we’ve got. Nuclear nonproliferation is at the heart of the dispute, the perfect test case for international legitimacy. Standard-bearer for the international policy establishment Foreign Affairs features a running battle between optimists and pessimists. Professor Sumit Ganguly writes off illegitimacy as outdated:

The arguments the critics make are well-known and amply rehearsed: giving such a concession to India will reward irresponsible behavior (i.e., developing nuclear weapons while keeping aloof from the nuclear Nonproliferation Treaty regime); it will encourage further proliferation (from states such as Iran, North Korea, Brazil, and Pakistan); and it will spur sales to potential proliferators by other nuclear suppliers (such as China, France, and Russia). Even if familiar and superficially plausible, however, all these criticisms are without merit.

But former Assistant Secretary of Defense Ashton Carter argues that the international legitimacy of nonproliferation benefits U.S. interests directly:

A crucial but underappreciated element of a successful policy is getting as many countries as possible not to develop WMD in the first place. The United States has dissuaded Germany, Japan, South Korea, Taiwan, and Turkey from going nuclear by forging stable alliances that offer these countries better security than they could achieve through unconventional weapons programs of their own. A peaceful and just world order led by the United States is the reason why only a few of the world’s nearly 200 nations are proliferation “rogues.”

Ganguly is right that dealing properly with India despite the irregularities in nonproliferation policy that result. But Carter is just as right to insist that consensus and control have an inherent value — not just to “international peace and security” but to the tangible national interest of the United States. In a world where the only rule is there are no rules, it can be exciting but exhausting to be a hegemon. That the modern international order has often failed the world and disappointed American hopes to enforce it with a coalition of willing states does not mean that we should learn to do without an international order that works.

THIS IS THE REASON why Bush is right to have paid so much attention to the United Nations, and why Bolton is right to diligently earn the respect of his international colleagues. But it is also the reason why we should take a look at the institutions that work — NATO is paradigmatic for the U.S., and the EU for Europe — and ask ourselves why they do. The inevitable answer is that organizations like NATO and the EU embody the consensus that defined their creation. Nations that share that consensus apply for membership and are accepted upon meeting measurable criteria. The Kyoto treaty on global warming was bad, from this perspective, because it failed to hold all would-be member states to criteria acceptable to the membership as a whole.

As we think about the real and necessary project of overhauling the international order in tune with consensual legitimacy, we should be prepared to establish new institutions that reflect the desires of the world’s representative democracies — and in so doing, lift international law out of its own limbo.