Still, some things are known. Thomas Victor Fuentes, the FBI's top agent in Iraq, told reporters that between 1,000 and 1,500 lbs. of explosives were used in the blast. Mortar and artillery shells were bundled around a 500-lb. bomb. The munitions were all military grade, imported from the Soviet Union in the 1970s and '80s. Many U.S. and Iraqi officials believe that the bomb was a suicide attack (though even that is not absolutely certain), which could be telling. Baath Party and Fedayeen Saddam guerrillas have not used suicide bombs before. "It's not part of the Iraqi culture, military or political," says Mohammed Abdullah Shahwani, a retired general of the Iraqi special forces. But Ansar al-Islam, which was driven from its base at the northeastern border with Iran during the war, used suicide attacks last spring near Halabja, and an Iraqi intelligence officer working with the CIA says, "Our feeling is that Ansar are the most likely ones, even if it was financed or supported by someone else."

In the streets of Baghdad, many point the finger at al-Qaeda—and one Iraqi security source claims that there are 300 al-Qaeda sympathizers in Iraq, some of them graduates of three terrorist training camps, near Kirkuk, Karbala and Rawa. Only al-Qaeda members, says Karim al-Sabti, an art-gallery owner in Baghdad, "are heartless enough to target civilian targets. The Fedayeen Saddam or Baathists—you expect them to hit Americans." Certainly, al-Qaeda has threatened the U.N. before. In a November 2001 message, Osama bin Laden said, "The United Nations is nothing but a tool of crime" that "continues to sit idly by" while Muslims are "massacred." But secular Iraqis loyal to Saddam have also long hated the U.N. for imposing sanctions on their nation, and an Iraqi intelligence official says the mukhabarat, Saddam's security service, once studied how to hit U.N. targets in Kurdistan.

With such a plethora of possible adversaries, pity the task of U.S. military planners charged with ensuring that Iraq becomes more secure. In an interview with TIME, Defense Secretary Donald Rumsfeld dismissed the idea that the solution is simply to send in more U.S. troops. Army General John Abizaid, head of the U.S. Central Command, says Rumsfeld, has "said repeatedly that he feels he has about the right number of U.S. forces." But both Rumsfeld and Abizaid want more Iraqis in uniform as well as more military contributions from other nations. "You want to put a bigger Iraqi face on it," says Rumsfeld, "and a bigger international face on it."

That's easier said than done. The Iraqi army was demobilized on the recommendation of U.S. proconsul Paul Bremer in May. Even Administration officials now agree, in hindsight, that the decision was a mistake, one that alienated a professional, secular organization and at the same time dispersed weapons all over Iraq. Retired General Anthony Zinni, a predecessor of Abizaid's at Centcom, agrees with that view. "The Iraqi military should have been decapitated, but its soldiers should have been kept in uniform and working with us. I'd get more Iraqis onto the street as soon as possible." That's a worthwhile goal, but it would be easier to put an Iraqi face on the occupation if the Governing Council—the 25-strong body of notables appointed by the U.S.—was more prepared to take a lead. So far, it has been a disappointment, hampered by divisions and unwilling to seek and take responsibility. "The problem," says a senior State Department official, "is that for 30 years these people have not exerted authority. They're not used to doing that."

The second of Rumsfeld's aims—to get more non-U.S. troops into Iraq—is no simpler to achieve. A multinational force led by Poland will soon begin operations south of Baghdad, but the U.S. would also like to see contributions from Turkey, India and Pakistan, all of which have effective armed forces and two of which—Turkey and Pakistan—are Islamic states. At present, however, the U.S. and Britain are the legal occupying power in Iraq, and most nations likely to be able to send useful forces will not do so unless the U.N has more authority there. After the Baghdad bombing, the Administration started to draft a new Security Council resolution that would call on member states to do more in Iraq, but Washington remained opposed to ceding any legal authority to the U.N. "This is not the moment for another theoretical discussion over who is in charge," says a senior State Department official. Maybe not, but without such a discussion the chances of getting a new resolution are slim. The French have made it plain that without some give by the U.S. on an expanded role for the U.N., a resolution will go nowhere. Still, as a senior French official told TIME, "in the medium term, there's an interest on all sides to start considering how a broader international force might be brought into Iraq."

But even if every nation in the world sent its best troops to Iraq, the task would still be enormous. As Army Major General Ray Odierno, commander of the 4th Infantry Division in north and central Iraq, predicted in July, the conflict in Iraq is becoming a classic case of what military thinkers call "asymmetric warfare," the kind that weak parties wage against strong ones. "They're going after softer targets and what we consider to be more of a terrorist-type activity," said Odierno. "The next step, to my mind, would be something like car bombs and suicide bombers." In such warfare, the initiative lies with the attacker, which is why Rumsfeld has always insisted that in the war against terrorism, the U.S. must go out and hunt down its adversaries.

The problem—one that all armies have faced when confronting guerrilla forces—is that search-and-destroy missions in urban areas run the risk of losing local hearts and minds, which is the last thing the U.S. needs in Iraq. U.S. officials may say, in the words of one White House aide, "We're more than happy to have the [2004 presidential] election become a debate on whether or not it was the right decision to go to war in Iraq," but an endless drip of American casualties might knock the edge off that bluster. And such an outcome is possible. "This is asymmetric warfare all the way, and in asymmetric you can't win," says a U.S. official closely involved in Iraq policy. "There isn't a military solution, and I'm not alone in saying that."

A political solution in Iraq—which is presumably the alternative—would require the gradual but steady transfer of authority to the Governing Council; a new constitution; the establishment of honest police, legal and bureaucratic authorities; and, in time, elections. It would mean, in short, the undramatic ability to use the good offices of outsiders—the U.N., aid agencies, nongovernmental organizations—to help Iraqis weave together a new society.

The real tragedy of last week is that there may have been nobody in the world better placed to do that than Vieira de Mello. "The last thing Sergio wanted," said Mark Malloch Brown, administrator of the U.N. Development Programme, "was for the Americans to hand power to the U.N. What he wanted was to accelerate the passing of power to Iraqis." The heartfelt anguish at U.N. headquarters at Vieira de Mello's death was not just because he was—as former U.S. Ambassador to the U.N. Richard Holbrooke said—"dazzlingly good-looking and charismatic" but also because in a long career that had taken him from one world hot spot to another, he had shown a rare ability to solve problems. Chosen by U.N. Secretary-General Kofi Annan to be in charge of nursing East Timor to independence from 1999 to 2002, Vieira de Mello performed brilliantly, taking a ravaged country and helping its leaders help their own people back to safety and security. "He had two skills that you don't usually find in the same person," said Holbrooke, who was a friend of Vieira de Mello's for more than 20 years. "He was a consensus builder, but he wasn't a lowest-common-denominator person. There was only one Sergio." Now he's gone.

—With reporting by Massimo Calabresi, James Carney and Mark Thompson/Washington; Simon Crittle/New York; Bruce Crumley/Paris; and Hassan Fattah, Aparisim Ghosh, Vivienne Walt and Michael Ware/Baghdad

1 | 2

	Premium Content