HADITHA, Iraq -- They stormed the insurgent-ridden city of Fallujah, returned home, and now are back in Iraq's most troubled province -- all in 10 months time.
Some prefer this hectic pace. "I didn't join the Marine Corps just to stand around," said Lance Cpl. Giovanni Perez of Los Angeles.
But for others, the demands of the overstretched U.S. military are just too much, regardless of the bonuses being dangled before them to re-enlist.
"I get out of the Marine Corps in seven months and I can't wait," Cpl. Daniel Trigg of Olympia, Wash., said while guarding a mosque where a large cache of insurgent weapons was being removed.
Trigg is on his third tour in Iraq in three years. His last tour had him in the southern city of Najaf, where U.S. troops fought fierce battles with Shiite Muslim militiamen last year.
For Lance Cpl. James Whelan of Kalamazoo, Mich., coming back is worth it. "As long as we clean up our mess and get this country back up on its feet," he said, leaning against a palm tree and scanning a thicket of grass. Just 20, he also is on his third tour in Iraq.
Their unit, the 3rd Battalion, 1st Regiment from Camp Pendleton, Calif., is one of three Marine battalions sent to Iraq three times.
Last November it joined in the battle for Fallujah, where several of its Marines were killed and dozens earned Purple Hearts while clearing out insurgents. Now it is trying to tame Anbar Province's Sunni Arab cities in the west that previously had no U.S. or Iraqi security forces.
The task is not easy. The unit they replaced suffered 48 deaths during a seven-month tour, and letters posted on a mosque by a former Iraqi policeman begging for forgiveness from al-Qaida members indicates the difficulty of rebuilding a local security force.
Marines note the war, at least in this region, has evolved since their last tour. Insurgents are now hiding instead of controlling entire neighborhoods.
Some Marines say this is a more challenging task than simply using the military's superior arsenal against gun-toting insurgents holed up in homes.
"It's harder. Before, you could just shoot a tank round through someone's window," said Sgt. Jesse Zunke, a squad leader from Reno, Nev., comparing the insurgency in Haditha to the militants who once swaggered through Fallujah.
"Now it's just playing detective and meeting these people," Zunke said shortly before an explosion rippled through the city, the latest of dozens of roadside bombs to be discovered and detonated.
The Marines focus on finding weapons and trying to collect information in an area where allegiances often change and true sentiments are hard to identify. On Friday, a large Sunni mosque blared messages supporting U.S. forces from loudspeakers, according to military translators -- but it was the same mosque where the arms cache had been found the day before.
For Marines who have been to Iraq before, the latest seven-month deployment is easier because of their experience, although some feel they are testing their luck.
"I'm a little less nervous this time because I know what to expect," said Lance Cpl. Kemny Kim of Houston, who got two Purple Hearts for wounds during his prior tour.
Kim talked as he searched through groves of palm trees along the Euphrates River, chewing on pomegranate seeds and a pear offered by a farmer. His brother, also a Marine, just returned home from a tour in Ramadi.
Marines said their prior experiences had them prepared for whatever comes in an area where 20 Marines were killed in August alone.
"You can tell the Iraqis who are scared because we're here and those who are scared because they're bad," said 1st Lt. David Jackson of New York.
Repetitive patrols through mostly empty streets, with only the sound of boots softly crunching on sandy roads and the hum of warplanes above, are relieved by an old Marine tactic -- jokes and pranks.
As a young man on a bicycle approached a patrol, the lead Marine instructed the man to raise his hands and lift his shirt to check for explosives -- then slap one hand on the opposite arm, then behind his head. It was the Macarena dance, laughing Marines noticed, before they let the man cycle past with a broad smile.
Marines waiting to scale a wall during house-to-house searches in 90-degree weather jokingly described their feelings: "Outstanding," said one smirking Marine. "This is the greatest feeling in the world," said another as the call to prayer wailed from a mosque a few blocks away.
"It's kind of like you never left. We're all used to it," Zunke said before his squad finished searching a block of houses and returned to their makeshift home in a school.