With violence at a low point in Iraq compared with earlier years, and with the Strategic Framework Agreement between Washington and Baghdad now in place and restricting independent action by U.S. forces, boredom is increasingly an enemy for many combat soldiers and Marines.

Operations are still staged against terrorists and extremist groups, but now they're conducted with Iraqi Security Forces in the lead -- and on their timetable.

Americans routinely roll out on mounted and dismounted patrols, but unless attacked, in imminent danger or they see a definite security crime being committed, they can't detain without a court-issued warrant.

Forward Operating Bases and Combat Operations Posts are closing completely or being handed over to Iraqi troops. By the end of June, U.S. forces will have withdrawn from cities, towns and villages to more isolated facilities.

Those COPs, placed in villages and neighborhoods, were a major feature of the "clear, hold and build" strategy of Gen. David Petraeus. They established a permanent security presence. They facilitated daily interaction between soldiers and Iraqi civilians.

"I came to Iraq ready for war," a soldier scribbled on a toilet wall at a base outside Baghdad, "then peace broke out."

An Army lieutenant at a COP here in Baquba, the capital of restive Diyala province, took a pragmatic bottom-line view: "Boredom is a good problem to have over here, especially when you consider the alternative."

About 4,273 Americans have died in Iraq since the March 2003 invasion to rid the country of Saddam Hussein. In 2007 the number of U.S. military combat and non-combat deaths was 904, according to Department of Defense statistics compiled by iCasualties.org. Last year the number dropped to 314 following implementation of Petraeus' counterinsurgency strategy late in the previous year.

Combat and non-combat U.S. deaths last month were 16 (about 10 from accidents), compared with 40 in January 2008 and 83 in January 2007. The average number of attacks of all kinds late last year averaged 10 per day for the country as a whole, compared with 180 a day in late 2007, military spokesman Brig. Gen. David Perkins said.

American troops a year ago did a constant, mental balancing act when outside the wire of their bases patrolling villages and neighborhoods and conducting raids to catch terrorists or to gain information. "Be a friend to every Iraqi you meet," a sign in a Marine base in Anbar province said, "but have a plan to kill them."

Soldiers and Marines rode the swings of that emotional pendulum several times a day, or, as one said, sometimes repeatedly within the same hour. But it was a different Iraq then.

That's not to say Iraq is no longer a dangerous place. It is, very much so. Al-Qaida and other extremist cells still operate in Baghdad and elsewhere, albeit in smaller numbers, with less material wherewithal and with dwindling public support or acquiescence. Mosul, the capital of Ninawa province, remains al-Qaida's last urban redoubt.

Diyala remains volatile. Al-Qaida cells are in areas close to the province's border with Iran, there is tension between Arab Iraqis and Kurdish Iraqis in the north, and Shiite and Sunni extremists stir the pot elsewhere, said Col. Burt Thompson, commander of the 1st Stryker Brigade Combat Team, based in Baquba.

But the statistics show the difference between early 2008 and today. So do children playing in the streets and customers crowding marketplaces.

It could be easy for complacency to mix with the boredom of routine here. The nightly booms of an artillery battery firing illumination rounds kept adrenaline flowing then on FOBs and COPs, as did the constant heavy traffic of troops in armored vehicles going out of the wire into harm's way.

On FOBs, which many soldiers never leave since they perform the support and administrative tasks of an army in the field, no one missed the disheveled, tired and quiet men in the dining facilities following missions. Neither did anyone fail to notice the frequent blackouts on telephone calls home or Internet use when fatalities occurred.

But U.S. troops aren't allowing malaise to happen. Each pre-mission brief -- whether the mission is to run supplies to an outpost, join Iraqi forces in a sweep or visit a neighborhood -- includes updated threat assessments based on recent incidents and intelligence. They also involve the soldiers answering questions on Rules of Engagement (the stages of action before firing a weapon at an Iraqi), procedures to be followed in case of IEDs, medical treatment and evacuation drills, vehicle rollover response and ambush reaction. And there are exhortations repeated during the missions to keep focus.

"Stay safe," soldiers say to others heading out the wire. It's not a meaningless, hackneyed phrase like "Have a nice day." It's a poignant wish and prod to stay focused.

Terrorists and extremists also help. The daily reports from Iraqi Security Forces on IEDs found and destroyed are noted before missions. So, too, are significant acts and intelligence reported by American units.

And there are the IEDs that escape detection and detonate.

Prior to provincial elections on Jan. 31, a platoon from Charlie Company, 1st Battalion, 5th Infantry Regiment, was on its way for a routine visit to Iraqi police stations in the Tahrir district of Baquba to check on Election Day security plans. A bomb explosion temporarily diverted them from their mission.

It wasn't a large bomb; few people were around when it went off on 40th Street, and injuries were minor. But the explosion and the shredded body in the street of the man transporting the bomb when it went off were stark reminders to stay focused on threats, especially car bombs and one of Diyala's terrorist hallmarks, female suicide bombers.

"There are some cold women in Diyala," Maj. Jonathan Lauer, an adviser to an Iraqi army brigade, said to his men before leaving a COP. "There was one a few months back when a woman sat down in a cafe with her kid and then blew herself up."

Iraqi officials earlier this month said they had arrested a 51-year-old woman who confessed to recruiting scores of women as suicide bombers. Those women reportedly carried out 28 missions in Diyala province, in Baghdad (just 35 miles southwest of Baquba) and in other areas of the country.

"Complacency Kills," say signs posted around U.S. military installations. As security in Iraq improves and as U.S. troops move into the back seat in security operations, the slogan increases in importance.