FALLUJAH, Iraq -- Taking a short breather, the 21-year-old Marine corporal explained what it is like to practice his lethal skill in the battle for this city.
''It's a sniper's dream," he said last week in polite, matter-of-fact tones. ''You can go anywhere, and there are so many ways to fire at the enemy without him knowing where you are."
Sniping -- killing an enemy from long distance with one shot -- has become a significant tactic for Marines in this ''Sunni Triangle" city as three battalions skirmish daily with armed insurgents who can find cover among the buildings, walls, and trees.
Marine sniper teams are spread in and around the city, working night and day, using powerful scopes, thermal-imaging equipment, and modified bolt-action rifles that allow them to identify and target armed insurgents from 800 yards or more.
Sniping specialists -- there are several in Fallujah with the Marines -- say there might not have been such a ''target rich" battlefield for such shooters since the World War II battle for Stalingrad, during which German and Russian snipers dueled for months.
As a military tactic, sniping is centuries old; the first snipers used bows and arrows. Leonardo da Vinci is said to have been a sniper against the Holy Roman Empire.
Weapons change, but the goal of the sniper remains the same: harass and intimidate the enemy, make him afraid to venture into the open, deny him the chance to rest and regroup.
The Marines say their snipers have killed hundreds of insurgents, although that figure alone does not accurately portray the significance of sniping. A sign on the wall of the sniper school at Camp Pendleton, Calif., displays a Chinese proverb: ''Kill One Man, Terrorize a Thousand."
''Sometimes a guy will go down, and I'll let him scream a bit to destroy the morale of his buddies," the Marine corporal said, ''then I'll use a second shot."
In negotiations aimed at ending the standoff in the city, the insurgents have demanded that the Marines pull back their snipers.
A shaky truce exists between the Marines who surround the city and the fighters within the circle. But the cease-fire allows the Marines to carry out defensive operations within the city, which among other things they define as allowing fire on insurgents who display weapons, break the curfew, or move their forces toward US troops.
While official policy discourages Marines from keeping a count of the people they have killed, the custom continues. In nearly two weeks of conflict in Fallujah, the corporal from a Midwestern US city has emerged as the top sniper, with 24 confirmed kills. By comparison, the top Marine Corps sniper in Vietnam killed 103 people in 16 months.
''As a sniper your goal is to completely demoralize the enemy," said the corporal, who played football and ran track in high school and dreams of becoming a high school coach. ''I couldn't have asked to be in a better place. I just got lucky: to be here at the right time and with the right training."
The military has asked that sniper names not be published. Insurgents were said to have placed a bounty for the killing of any Marine sniper. A website linked to the insurgents tries to provide information on snipers and their family members. During Vietnam, the Viet Cong also put a bounty on snipers.
''If you're going to be a sniper," the corporal said, ''you just have to accept the things that come with it."
Marine snipers, whose motto is ''One shot, one kill," fire from rooftops in crowded urban areas of Fallujah, as well as while exploring the city by foot. It sometimes takes hours to set up a shot; the sniper hides in the distance, waiting for the opportune moment.
Officers credit the snipers, all enlisted men, with saving Marine lives by suppressing enemy fire and allowing their comrades greater freedom of movement. ''The snipers clear the streets," Captain Douglas Zembiec said. ''The snipers are true heroes."
Sniper teams have come under fire and suffered casualties. Marine intelligence suggests that the insurgents, using Russian- and Chinese-made rifles and optics, have their own sniper teams, but no Marines have been killed by sniper fire in Fallujah.
Unlike most Marines, the sniper sees the enemy before shooting. The enemy has a face.
Most combatants get only a glimpse of their enemies. The distance is too great, the firing too rapid. But the sniper, with time to set up the shot, sees the victims more clearly through a powerful scope: their faces, their eyes, the weapons in their hands. And their expression when the bullet hits ''their center mass."
''You have to have a combat mind-set," the corporal said.