Few foresaw that winning the recent war in Iraq would prove so easy. Fewer still predicted that winning the peace would prove so difficult. While power is relatively quantifiable, legitimacy remains elusive. In Iraq, as elsewhere, the challenge lies in combining the two.

There are three distinct but interconnected issues at the heart of that challenge.

The first is the 21st-century role of the United Nations. In his upbeat address to the General Assembly on Sept. 23, President Bush, in search of legitimacy, called on the United Nations to play a bigger role in assisting Iraq — to train civil servants, to draft a Constitution and to organize elections. He also foresaw a role for UNICEF and the World Food Program. This was consistent with an administration view which sees the United Nations more as a kind of plumber-cum-nursemaid service than as the repository of international legitimacy. U.S. plans foresee real power in Iraq remaining for some time in the hands of Paul Bremer’s Provisional Authority. But while power without legitimacy may work in wartime, it cannot work in peacetime.

Kofi Annan recently warned that the U.N. had come to a “fork in the road.” Its structure no longer reflects the spread of power around the world. Hence, its legitimacy is weakened. It also suffers from a chronic shortfall between supply and demand. Its services are increasingly called upon around the world — testimony to its legitimacy. But its funds, manpower and resources remain woefully inadequate — witness to its limited power. Above all, in the post-Sept. 11 world, a new set of rules for addressing problems such as failed states, WMD proliferation and terrorism, as well as agreed guidelines for preemptive and preventive warfare, are urgently required. The U.N. alone can confer the legitimacy without which, at one level, power is ultimately powerless.

The second issue at the heart of today’s debates is the speed and manner of sovereignty transfer in Iraq. For France’s Jacques Chirac, the solution lies in shifting the transition process from the military sphere to the political sphere — in moving from occupation to organization, from power to legitimacy. France attaches overriding political significance to an immediate declaration of Iraqi sovereignty, even while recognizing that any interim government will lack effective political control. This approach underestimates the practical problems of reconstructing a country as complex and problem-ridden as post-Saddam Iraq. Legitimacy without power is like gin and tonic without the gin.

On the other hand, to prolong indefinitely the exercise of power without legitimacy is a recipe for disaster. The third issue is, precisely, that of the limits of military power. There are currently 150,000 troops in Iraq, of which all but 25,000 are American. Since UNSC Resolution 1483 which effectively “recognized” the occupation authority, these troops have a vestige of legitimacy. But it is unclear what real power they possess. The United States has called on other nations to help out. There are two problems with this. First, there is the political delicacy of sending troops into a quagmire which gets more violent by the week. But second — and potentially more significant — there is the stark fact that global troop capacity is in short supply. It has been calculated that a country with the size and population of Iraq requires at least 250,000 troops to enforce stability and to train local police and armed forces.

The United States is stretched to the limit and is calling up more reservists. British, German and most other European forces are similarly overstretched. The United States was hoping for commitments from South Korea, Turkey, India and Pakistan. None has been forthcoming — not only because such deployments would be massively unpopular domestically, but also because the numbers of appropriately trained troops do not exist. One study has concluded that even if the United States succeeded in tapping into the relevant resources of every country with spare capacity, it would still be hard put to muster the magic number of 250,000. Meanwhile, in Iraq, acts of sabotage and resistance multiply.

Ironically, France currently does have spare military capacity — of the appropriate sort. But in his recent interview in the New York Times, President Chirac implied that France will not send those troops into a power vacuum without first establishing what he considers to be Iraqi legitimacy. And so we come full circle.

The answer lies in give and take on both sides. The U.S. must propose a resolution with a clear timetable for transfer of responsibilities (even if this is more protracted than some French plans foresee) and a clear statement of political intent with respect to Iraqi sovereignty. Anything less will get a mixed reception in the Security Council — which defeats the object of the exercise. For their part, reluctant partners — France foremost among them — must cease to be ambivalent about the current situation. Destabilization, or even worse, breakdown in this part of the world would be disastrous for everybody.

Greater international willingness to contribute power to the vacuum will increase the legitimacy of the United Nations, which must ultimately consecrate the transfer of Iraqi sovereignty. Greater power to the United Nations will increase the legitimacy of those who exercise power in its name.

Only through combining power and legitimacy can either force realize its true potential.

Jolyon Howorth is Jean Monnet Professor of European Politics at the University of Bath (U.K.). He is currently a visiting professor of political science at Yale.