CAMP FALLUJAH, Iraq (Nov. 28, 2006) -- "Adrenaline rush" doesn't describe what it's like to stand next to a tank as it fires. It's as if Thor, Norse god of thunder, got his Viking shorts in a bunch because someone makes a noise louder than him, so he grabs hold of the adrenal glands and squeezes for all he's worth. The ear-cracking, rib-crunching, earth-shaking "boom" of the M-1A1 Main Battle Tank's 120 mm main-gun round firing is nothing short of unnatural. It's the sound of a thousand trees snapping in half all at once, the smack of a semi truck...