He is an irrepressible man with full, close-cropped gray hair, blue eyes and a radiant smile, and as he told me about the early days, he recalled his disbelief at the men who were drawn to the company. "He wants to work for me?" he said he thought, over and over. But his modesty went only so far. "Rock stars like to work with rock stars," he said.

When it needed cash, to pay employees or buy equipment or build camps, it dispatched someone from Chicago with a rucksack filled with bricks of hundred-dollar bills. "All the people in Iraq had to say is, 'We need a backpack,' Or, 'We need two backpacks.'" Each pack held half a million dollars.

Suddenly, we were braking. Traffic crawled and doors were "cracked": doors are opened as little as possible, and rifles are pointed out -- the response when other vehicles get too near. The windows on armored vehicles are so heavy that they don't reliably roll up once they're rolled down, so they don't use the windows to point their guns. The door-cracking is rehearsed procedure; they can ride this way at top speed, leaning out to aim their guns in warning, or to put bullets into the engine of an oncoming car.