In the first weeks after the fall of Baghdad in April 2003, Iraqis would stop Americans on the street and ask who was in charge of the country. No one seemed to know. The Iraqi leadership had vanished, and the institutions of the state had collapsed.

The Iraqi exile politicians returning to Baghdad imagined that power would be handed quickly to them, but they were a contentious group with dubious backing inside the country. The American military, which had led the drive to overthrow the regime of Saddam Hussein, was now standing back, unwilling to intervene to stop the rampant looting and impose civil order. The civilian reconstruction group, under retired Army Lieutenant General Jay Garner, had no practical or legal authority and few assets to run the state. They saw themselves as liberators and were hesitant to assert themselves as rulers of Iraq. At a meeting in late April at the Baghdad convention center between coalition administrators and Iraqi notables, a tribal sheikh stood up and asked, “Who’s in charge of our politics?”

“You’re in charge,” Garner replied. There was a collective intake of breath among the Iraqis in the room. An American official at the meeting later told me, “They were losing faith in us by the second.”

By the middle of May, Garner had been replaced by L. Paul Bremer III, who had the status of presidential envoy and the legal backing of United Nations Security Council Resolution 1483, which acknowledged that the United States, the United Kingdom, and their coalition allies were the de facto occupying powers of Iraq. Thus began the troubled, year-long life of the Coalition Provisional Authority. Where Garner had tried in his laid-back way to ease a rapid transfer of power to the Iraqis, Bremer acted as if he was in charge. In the words of one C.P.A. official, the “arrogance phase” of the chaotic early days, with its rosy assumptions, had given way to the “hubris phase” of a heavy-handed occupation. The C.P.A. eventually issued dozens of legal orders, with the goal of remaking Iraq into a free-market democracy.

At least some of those orders were of doubtful validity under international law. The 1907 Hague Regulations and the fourth Geneva Convention of 1949 define the position of an occupying power in carefully delimited terms, as place-holder and caretaker rather than as a normally functioning government. Occupation brings with it a balanced set of responsibilities and prerogatives. According to Article 43 of the Hague Regulations, it is the duty of an occupying power to “take all the measures in his power to restore and insure, as far as possible, public order and safety, while respecting, unless absolutely prevented, the laws in force in the country.” To promote public order, or to ensure its own security, an occupying power can repeal or suspend local laws, and introduce its own regulations (for instance by regulating the press or limiting the right of assembly). If it is necessary for imperative reasons of security, it can intern people without trial, though this must be done according to a regular procedure with a right of appeal and regular (ideally six-monthly) reviews. Domestic courts must be allowed to function wherever feasible, enforcing those local laws that have not been suspended, and the occupying power can also establish its own tribunals to enforce its penal regulations, so long as no one is sentenced without a fair trial.

Occupiers are also obliged to look after the welfare of the civilian population, ensuring as far as possible that it has adequate food, water and medical treatment. The Red Cross and other humanitarian relief groups must be allowed to operate and distribute supplies if the occupying power cannot meet the needs of civilians itself. It is forbidden for an occupying power to transfer civilians out of occupied territory, or to transfer its own civilian population in.

All these rules apply from the moment an occupying power actually
controls a body of territory, even if it does not acknowledge the title of occupier.

The laws of armed conflict allow some scope for occupying forces to alter the legal systems of the countries they control, but envisage that such measures be limited to those with short-term consequences. However at least since World War II there has been a contrasting strain of thought, arguing that transformation of the political system in place before occupation may in some cases be not only permitted but desirable. Even as the fourth Geneva Convention was being negotiated, the United States and its coalition partners were engaged in the complete remaking of Germany and Japan. In practice, the international community has been willing to accept such “transformative occupation” through endorsement by the United Nations Security Council, where it is aimed at promoting fundamental human rights or the principle of self-determination. The occupation of Iraq has tested the limits of this emerging consensus.

The military occupation of Iraq allowed public order to collapse and was never able to restore it, while the C.P.A.’s ambitions went far beyond merely administering Iraq until sovereignty could be returned. Order Number 39, which opened the Iraqi economy to foreign investment and allowed for foreign ownership of Iraqi assets, imposed just one of many far-reaching changes in Iraqi law. C.P.A. officials pointed to language in Security Council Resolution 1483 that instructed the authority to “promote the welfare of the Iraqi people” and provide “economic reconstruction and the conditions for sustainable development.”

But the C.P.A.’s project was ideological, not just administrative: the
radical transformation of Iraq. If it had paid more attention to “the welfare of the Iraqi people,” and less to the vision of the Republican administration in Washington, the C.P.A. would not have tried to privatize state-owned industries in a country where employment ran well over fifty percent. And if they had taken their responsibilities under the Geneva Conventions more seriously, American commanders would have resisted the pressure from their civilian bosses to use coercive interrogations in the effort to snuff out the insurgency. The result of this failure was the scandal of torture at Abu Ghraib, the single worst mark against the Coalition Provisional Authority. The laws of occupation don’t merely serve to protect the rights of the occupied—they also protect the perception of the occupier.

Pushing the envelope of international law was not the occupation’s core problem. Whether or not its authority was legal, it was increasingly perceived by Iraqis as illegitimate. This perception had at least as much to do with the chaos and incompetence of the C.P.A.’s rule as it did with the original invasion. When I met Bremer at his office at the Republican Palace in the secure Green Zone, he told me that the closest historical precedent for his job was that of the allied military occupiers of Germany and Japan after World War II. This was a misleading analogy, and it helped to explain the C.P.A.’s many mistakes. Those postwar occupations were legitimate, in the eyes of the world and of the defeated nations. General Douglas MacArthur could write the constitution of Japan in a way that even Bremer couldn’t force an American draft constitution down Iraqi throats. Whatever his legal authority, MacArthur had the power of the moral victor. The measure of the C.P.A.’s illegitimacy in the eyes of Iraqis lay in the rising number of attacks against foreign soldiers and civilians during the year of the formal occupation. Some Iraqis voted with roadside bombs and Kalashnikovs; others stood aside and refused either to join in the reconstruction or to resist it. By June of 2004, when Bremer was signing a flurry of last-minute legal orders before the transfer of sovereignty, Iraqis had definitively rejected the occupation, and very little of the C.P.A.’s efforts survived the restoration of self-government. Bremer and his aides flew home, and Iraq returned to itself.

In his memoir “My Year in Iraq,” Bremer describes a dark moment in which he concluded that the Americans in Iraq had become the worst of all things, “an incompetent occupier.” The only justification for a prolonged occupation by a foreign power, such as the world hadn’t seen since 1945, was a practical one: that post-Saddam Iraq was too shattered and divided to govern itself. Only an occupation that was able to reconstruct the country and usher in genuine self-rule could have overcome all the counts against America in Iraq. From the beginning, the occupiers had to navigate between two imperatives: to exercise enough control that Iraq stood a chance of succeeding, and to yield enough control that Iraqis cooperated with the project. In the end, the C.P.A. accomplished neither.

(See detention and interrogation; due process; Iraq.)