The deteriorating sense of order in Iraq presents the United States with two possibilities it had hoped to avoid: increasing the number of US forces there, or taking steps to internationalize security forces on the ground.
For the Bush administration, dipping deeper into the military reserves may be politically unpalatable - and may not yield, in any case, the kind of personnel a postwar reconstruction requires. At the same time, the resistance of countries to have their troops operate under US auspices means Washington would have to accept some international controls to get more foreign participation - something that is anathema to the Pentagon in particular.
But with US efforts in Iraq suffering repeated setbacks - exemplified by Tuesday's horrific bombing of the United Nations offices in Baghdad - calls for more forces are multiplying, as is the pressure to give the reconstruction less of an American face.
It doesn't help that the Baghdad bombing was followed by another devastating suicide attack in Jerusalem. Though unrelated, it serves as a reminder of the grim future the US could face in Iraq if a sense of foreign occupation takes hold. The need, experts say, is to convince the Iraqi people that the US-led remodeling of their country is working - and perhaps to quicken the transition to local governance.
"The US either has to increase its commitment in terms of bodies on the ground, or it will have to turn over more of the work to other countries with peacekeeping experience," says Nikolas Gvosdev, a security expert at the Nixon Center in Washington. "But that would mean accepting less US control and more international management. It's a dilemma, and one that doesn't please" the Bush administration.
The concern taking root among Democrats and even some Republicans in Washington is that a faltering sense of order in Iraq could derail the country's reconstruction and feed extremist, anti-American forces around the globe. As a result, pressure is growing for the US to change its approach.
US Sen. John McCain (R) of Arizona, who was in Baghdad at the time of the UN bombing, says his visit convinced him the US must increase its forces in the country. To Sen. Joseph Lieberman of Connecticut, a Democratic candidate for president, it's time for the US to stop going it alone and to give the Iraq occupation more of a global face. The US "must directly involve the United Nations and commit greater force" in Iraq, he said in a statement this week.
The UN bombing left some administration officials hoping the particular target would convince more countries of the importance of making Iraq's reconstruction a success. Yet the strike may not be enough to break administration resistance to going back to the UN, hat in hand. "The administration hasn't reacted to what has been going on in Iraq for a while, so I don't think the bombing of the UN will be the trigger," says Patrick Lang, a retired Middle East specialist from the Defense Intelligence Agency. "They're just not there yet."
For one thing, sending more US troops would further highlight how thinly stretched the US military is - something Mr. Lang says Defense Secretary Donald Rumsfeld has no desire to accentuate.
Then there is US resistance to accepting some international control in Iraq. "There's this feeling the UN is slow and disorganized and would mess things up," says Richard Murphy, a former US diplomat in the Middle East now at the Council on Foreign Relations in New York. "That's costing us."
Mr. Murphy sees no single force masterminding violent resistance to the US in Iraq, no "spider in the web" drawing together the remnants of Saddam Hussein's Baathist Party, former army or security officials, and the "jihadis" who have come from outside Iraq to defend Islam. "They all fit with Iraq's history of a fierce hating of outside domination," he says.
Coupled with that sentiment is growing bewilderment among Iraqis about why the US is not more quickly returning the country to normal life. "They remember that as terrible as Saddam was, he got the country back on track with amazing speed after [the first Gulf War in] '91," says Murphy.
That experience tells Iraqis that rebuilding their country is possible. But putting them more in charge of their future - getting the police and elements of a new military up and running, for example - has to move faster, experts say. "We don't have enough people in there, and we're finding that other countries have more of the kind of people we need," says Mr. Gvosdev.
Indeed, for some analysts, it is not more soldiers that are needed, no matter where they are from, but experts in a variety of fields who can help give the country a sense of order and progress, and prepare Iraqis to take over for themselves.
"A hundred more trainers for all the services the Iraqis need to take on themselves are much more important at this stage than 1,000 more young men to guard locations," says Patrick Clawson, deputy director of the Washington Institute for Near East Policy. "We've been slow at that, but sending in any more combat troops is not going to address that central issue."