"I'll have to use it eventually," he says, squinting in the late-afternoon sun as a half-dozen illegals dart through a hole in the fence a stone's throw from his property line. "The house has been broken in four times this year, but I've always been away. The odds are, next time I'll be home.
"And if I am, there is going to be some dead Mexicans laying out in the yard."
As if to punctuate his point, a distant gunshot rings out somewhere down the fence line. Gunfire, locals say, can often be heard after dark on both sides of the border.
Maria Nochez, who lives with her two young boys a block away from the fence, makes her children sleep on floor mats--after a presumably random gunshot shattered their bedroom window one morning just before dawn.
"More drugs got run across my front yard last month than got sold in all of New York City last year," Nochez says, "and those guys carry big guns. My kids play inside."
But as bad as conditions may be for residents on both sides of the border, it is far worse for agents of the U.S. Border Patrol. They are hunkering down for war--and for them, the military analogies come easy.
On a recent morning at the main Border Patrol station in Nogales, Joseph Harris, the station commander and an 18-year veteran of the patrol, sighs that the Arizona border is "like Vietnam."
"The only difference is that we know where the enemy is, which is to say that he is everywhere. They are sweeping over us," Harris says. "My people are getting their butts kicked."
The only way to maintain discipline and morale under such warlike conditions, Harris says, is to enforce a strict code of military conduct. Officers can be given written reprimands for being five minutes late to work, for having their uniform in less-than-perfect shape, and for a variety of other minor offenses.
"It may seem like little things, but we have to be able to rely on each other down to the minute," he says.
"All we have is each other, and we have to stay together, looking and acting like a team."
The team has tough opponents. On this morning, agents are busy carrying boxes of heavy new Kevlar riot shields into the patrol's bunkerlike office a few miles north of the border. They're needed, Harris explains, to protect officers from rocks that cascade daily over the border fence, thrown by young wanna-be illegals.
"They do it to drive us away from the holes in the fence line, they do it to show their contempt, they do it for fun," says Steve McDonald. "They do it, most of all, to hurt us."
Patrol agents, McDonald says, have developed a strategy for avoiding the rain of rocks. "Your instinct is to run away, but the best strategy is to run toward the rock thrower, toward the fence," he explains. "It's more difficult for them to arc it over and hit you if you're clinging to the wall."
While the sight of macho federal lawmen scampering for cover from rocks tossed by pubescent Mexican kids may seem ludicrous, it isn't really a laughing matter. The damage the flying hunks of asphalt and granite can do is evident on the dented fleet of green and white Suburbans agents use to patrol the border.
"The trucks are targets," McDonald says. "And we've lost dozens of windshields to thrown rocks. Having a windshield explode in front of you, with glass flying everywhere, can really make you jumpy."
Civilians have also become targets. In a recent rock-throwing incident in Nogales, a large chunk of broken, jagged asphalt crashed near a woman and her baby carriage. "Some of these illegals are just wild men, they don't much care what they're throwing at," McDonald says. "They just want to hit something."
The uncontrolled "rockings" have become a symbol of the impotence of the federal presence on the border--and never more so than earlier this year, when the Border Patrol was forced to move agents back from the actual fence line to positions a block away.
It was the first time in memory that officers have in effect abandoned a U.S. border. Although many agents have been moved back this month into what McDonald calls "the hot zone," it is uncertain how long they will remain. It isn't always just rocks that are whizzing over the border fence.
Twice in February, bursts of automatic weapons fire coming from a border neighborhood in Nogales, Sonora, called Buenos Aires--an area, McDonald says, where even Mexican federales fear to tread--sent agents scrambling for cover. No one saw exactly where the shots were coming from.