Oliver North

TUCSON, Ariz. -- "We're under siege," said rancher Ed Ashurst as he pointed to where he had tracked the killer of his friend and neighbor to the U.S.-Mexico border. "Five years ago, we didn't even bother to lock our doors. Now my wife and I carry firearms everywhere we go."

John Ladd is a fifth-generation cattle rancher in southern Cochise County, Ariz. The southern boundary of his family property is a 10-mile stretch of steel fence erected by the U.S. government. On the other side of the fence: Mexico. He told us, "Mexican drug cartels are running this part of America."

The poet Robert Frost posited that "good fences make good neighbors." From what our Fox News' "War Stories" team documented this week, that's not the case here in southern Arizona, where "the fence" on the U.S.-Mexico border remains unfinished. According to many levelheaded, beleaguered Americans here, the fence is little more than a "speed bump" for drug couriers, killers, human smugglers and lesser criminals flooding into our country.

Wednesday night, just hours after Barack and Michelle Obama and their doting supporters dined on Martha's Vineyard, our team, accompanied by members of the Cochise County sheriff's Border Interdiction Unit, walked up a quiet hilltop a few hundred yards north of the "fence." There we watched through night-vision devices as a group of individuals approached the Mexican side of the steel barrier, timing their movement with the passing of U.S. Border Patrol vehicles.

By the time we departed for another location two hours after dawn, the "jumpers" -- all wearing backpacks -- had yet to make it into the U.S. Heartened by what we had seen, I said to one of the deputies, "It looks as if the fence worked."

"Yeah," said one of our guides and well-armed protectors, "but they have spotters who saw us leave. They will try again. Maybe we'll get 'em, maybe not. But there are a lot more of them than there are of us. And they are better-armed than we are because the cartels have bigger budgets."

The numbers verify the claim. Joaquin "El Chapo" Guzman -- a multibillionaire who heads the Sinaloa cartel just across Arizona's border -- commands an army of more than 11,000 "shooters" equipped with heavy machine guns, other automatic weapons, rocket-propelled grenades and armored vehicles. That's more than twice as many "troops" available to the U.S. Border Patrol, Arizona Department of Public Safety, Indian Affairs police and county sheriffs on Arizona's border.

Oliver North

Oliver North is a nationally syndicated columnist, the host of War Stories on the Fox News Channel, the author of the new novel Heroes Proved and the co-founder of Freedom Alliance, an organization that provides college scholarships to the children of U.S. military personnel killed or permanently disabled in the line of duty. Join Oliver North in Israel by going to www.olivernorthisrael.com.