Is this me? Eight o'clock on a Tuesday evening, I'm strolling down the ordinary street of my town carrying an M-16 rifle. Tonight it's my turn again to do shmirah, guard duty, a chore required about once a month of every male resident here at Beit Yattir, the West Bank village where I live.

The slender M-16 is a meter long and weighs about seven pounds. I like it. I appreciate the smooth simplicity of its design, and its oiled, metallic weight feels good in my hand. And beyond the physical satisfactions of a gun, I understand that I am in the presence of the Angel of Death. Fear and reverence abide with me as well.

As a safety drill, I pull the bolt back twice to check visually that no bullet is in the chamber; then I move the selector switch from safety to semi-automatic and, aiming the rifle away from the houses, pull the trigger. Click. No bullet. I shove the curved ammunition clip up into its shaft, where it locks in with a satisfying thump and click. The gun is at rest, all its power latent.

Part of what I like about shmirah is that it so clearly distinguishes my Israeli present from my American past. In my past there are no firearms. My grandfather, who escaped from the Czar's army circa 1900, was the last male in the family to do military service. We're urban American Jews, lovers of peace and the life of the mind; less nobly, we shrink from the notion of responsibility for our own protection.

I slip behind the wheel of the security Jeep, tucking the M-16 into the space between the front seats. With another man - and another rifle - for company, I'll spend the next five hours slowly driving the roads of our village, concentrating on the dark, unpaved perimeter roads, most of them no wider than the vehicle, shining a searchlight over the dark, rocky landscape as if expecting to pinpoint intruders coming to disturb our nighttime quiet.

In actuality, an intruder would have to be retarded to get caught by the Jeep's searchlight. Anyone out there would see our lights coming from far away, lie still behind a rock, and wait for us to pass. Shmirah is partially symbolic: We are letting our Arab neighbors know that we are on guard and that, as driveway signs put it in the U.S., any intrusion will be met with an armed response.

My training for this duty was minimal. First a fellow resident named Itamar, a skinny, cheerful guy about 30, taught me to handle the unloaded rifle - how to hold it, how to stand balanced for the best shooting, how to fire. We were in his living room, with two of his children, 3 and 5 years old, looking on with interest - mostly at me, since I was a stranger, whereas the weapon was a familiar object. It felt peculiar to stand aiming a rifle at the bookshelves in this pleasant fellow's parlor.

A week later, some 15 of us went for practice to the outdoor shooting range in the nearby village of Maon. About half the group were women who, though free of the obligation of shmirah, wanted gun training in case they ever needed to use one. We were coached through firing 15 rounds with an M-16 (five standing, five kneeling, five lying down) and then an equal number with an Uzi - the rifle stock kicking back into the shoulder, the explosive blasts sharp in the ear. Afterward, we strolled down across the no-man's-land between us and the targets to see how well we had done. There the holes were, some of them pretty good shots, chest or stomach high, definitely sufficient to stop the human animal. I was ready.

My shmirah partner and I chat as we drive, getting to know each other, then gradually fall silent, thinking our own thoughts. A wild rabbit, panicked by our spotlight, leaps away over rocks. In the early part of the evening, residents out for a walk or returning by car from work wave a greeting to us. At 9:30, we open the main gate for the local bus to BeerSheva. The evening drags on. Around 10:30 the teenage boys playing on the basketball court finally switch off the lights and disperse to their homes. Two dogs bark continuously in the Arab village below us. For a while, we park up on the hillside to enjoy the elevated view: the roofs and yards of our village, the highway raveling through hillsides to Jerusalem, the lights of Jewish and Arab towns stretching to the horizon. Then we go on our rounds again.

Shortly before 1 a.m., we wake two of the young soldiers sleeping in a trailer at the north edge of the village. Three soldiers are assigned to Beit Yattir on two-week rotations, and one of their jobs is to take over late-night guard duty on foot, walking the perimeter fences and checking the gates until sunup.

They are slow to wake. We wait outside until they stumble from the trailer with their M-16s slung over their shoulders, zipping up their khaki army jackets against the cold. We hand over the two-way radio that will connect them to the regional security base near Hebron, then park the Jeep. At last, my shmirah partner and I are finished.

Back in my house, I extract the ammunition clip from the M-16, check the chamber again, lean the rifle against a bedroom wall, to be returned to the village's security officer in the morning. Something about even these small formalities excites me, as if I am a little boy playing soldier, pretending danger and courage.

It is a foolish game, I remind myself. Although there has never been a terrorist intrusion at Beit Yattir, the neighboring village of Sussya has not been so lucky; it is not completely out of the question that I will one day be forced to face my fellow man with my weapon and his between us.

But not tonight. Tonight I can enjoy the ordinary peaceful quiet of my rural village. Nonetheless, before I go to sleep, I double-lock the door. This, I remember, was always my final gesture of the day in America, too. There, no less than here, a brutish danger lurks outside somewhere, unpredictable. Double-locking the door behind me, I recognize myself again.