The first time the United States took on Saddam Hussein, its motto was "overwhelming force" -- half a million troops swiftly kicked the Iraqis out of Kuwait.
The sequel is proving far more complex, but the U.S. has just half as many troops in the region, and fewer than 90,000 in Iraq itself.
Some military analysts have questioned that disparity, saying stiffer-than-expected Iraqi resistance underscores the gamble Defense Secretary Donald Rumsfeld and his war planners took in crafting troop deployments.
One analyst, Daniel Goure of the Lexington Institute, said this week that U.S. forces were "a division or two light." Another, retired Gen. Barry McCaffrey, told NBC News that the Pentagon had risked "disaster" by not sending enough troops to Iraq.
The argument goes that with more troops, the U.S.-led forces would have been better able to stave off the Fedayeen and other mobile militias that have attacked long coalition supply lines.
Some units on the road to Baghdad have had to be redirected into fighting back.
But Rumsfeld and his field commanders have bristled at such claims and contend the war plan is working excellently.
They point to such successes as securing key airstrips and oil fields, getting to within 50 miles of Baghdad within days and dropping paratroopers into northern Iraq.
At a Camp David news conference Thursday with British Prime Minister Tony Blair, President Bush sidestepped a question about whether the strong resistance U.S. troops faced in southern Iraq indicates the war could take longer than expected.
"This isn't a matter of timetable, it's a matter of victory," Bush said. "Saddam Hussein will be removed, no matter how long it takes."
Harlan Ullman, senior associate at Washington's Center for Strategic & International Studies and an architect of the "shock and awe" bombing strategy touted in this war, said critics of the troop deployment are mistaken, although many more soldiers will be needed in the peacekeeping and occupation phase.