To defeat the deadly insurgents it faces in Iraq, the US may have little choice but to shoulder forward in a long, hard slog.
The Pentagon is unlikely to order radical changes in tactics in response to recent deadly bombings, say experts in and outside the military. Nor are there new magic-bullet antiterror systems on the horizon.
Instead, the best option for commanders is likely to be continuous, marginal improvement in what they're doing now: patrol more, patrol better, train more Iraqi police, and, especially, focus more resources on understanding the foe.
"This war is sort of a terrorist operation ... and what you need to beat the terrorist is good intelligence," says Marcus Corbin, a senior analyst at the Center for Defense Information in Washington.
This week's string of deadly attacks in some areas of Iraq has rocked Washington policymakers back on their heels and led to calls for a reassessment of the US military effort.
On Tuesday unknown assailants struck again in Baghdad, assassinating a deputy mayor in a hit-and-run shooting. A car bomb exploded in the tense city of Fallujah, killing at least four.
White House officials said the attacks showed that anti-US elements were desperate to stop steady progress towards Iraqi normalization. But they also admitted that the ferocity of resistance to the US occupation has taken them by surprise.
"We didn't expect it would be quite this intense this long," said Secretary of State Colin Powell in a recent interview on NBC.
Deadly as they have been, the attacks so far are not of a scale that by themselves would drive the US military away, note experts. Some say it's important to note that one strategic aim of the Iraqi enemy is similar to the strategic aim of the North Vietnamese, during the Vietnam War: defeat the enemy by undercutting its political support back home.
Similarly, the Iraqi insurgents are clearly trying to discourage their fellow countrymen from cooperating with the Americans. "The most important thing is to make it clear that you can't be chased away, and that we're committed to the long term," says Lee Feinstein, acting director of the Washington program at the Council on Foreign Relations.
That being said, the US still has to show progress if the general Iraqi population is not to sour on their occupiers. Some experts say that if things are not on the upswing by spring, restiveness may spread to Iraq's silent majority.
This doesn't mean the US has only months to turn Iraq into Switzerland. It does mean that ordinary Iraqis need to come to believe that their lives are going to continue to improve, day by day.
"You have to both demonstrate that you're able to bring security to Baghdad, and you have to demonstrate that you're able to hand off responsibility for security to Iraqis over time," says Mr. Feinstein.
FROM a military standpoint, hunkering down might not help. The hotel hit by rockets on Sunday, killing a US officer, was within a secure area, after all. What's needed is more pressure, to disrupt plans. Many retired officers say that more US troops are needed, to mount more patrols. But others note that more US troops equal more targets - and that the first problem is not to find the enemy, but to figure out who he is and what motivates him.
There are hints that some of the suicide bombers who struck throughout Baghdad on Sunday were foreign terrorists, and not remnants of the Saddam Hussein regime. But the truth is that some six months after the fall of Baghdad, the US still doesn't really know who it's up against.
"We're trying to determine the nature of who these people were," said President Bush at his Tuesday press conference.
Intelligence resources might be better deployed. A recent report from the Center for Army Lessons Learned noted that the Army has 69 tactical human intelligence teams in the country - 15 fewer than needed. Those in place were producing far fewer reports than expected, the reported said.
Iraq's own intelligence capability might be reconstituted. Iraqis themselves could prove more capable of penetrating anti-US cells than US personnel have been.
"We are thinking seriously of having an intelligence organization," Hoshyar Zabari, foreign minister of the Iraqi Governing Council, told a Brookings Institution audience earlier this month. "You cannot run a country without an intelligence operation to identify all the sources of ... threats."
Intelligence has begun flowing in at a faster rate, according to Maj. Gen. Raymond Odierno, commander of the 4th Infantry Division in Iraq.
More and more tips are coming in every day, said General Odierno in a videoconference with Washington-based reporters.
"It is probably 10- or 20-fold more than when we first started here ... the number of people we have coming in to provide us human information," he said.
The information is also far more useful, about 90 percent accurate, said Odierno. Intelligence indicates that the amounts of money being paid by insurgent leaders to those willing to attack Americans has skyrocketed, from $100 this spring to $1,000 to $5,000. That inflation shows that fewer people are willing to come forward, said Odierno.
The armed services are working on new technologies that might help soon, such as new methods of fusing information gathered by unmanned Air Force drones with other sensors. But Odierno said that his highest priority was a technology that would allow him to jam or prematurely explode the improvised bombs being used against his troops.