Because they don't trust the cops.

KABUL, Afghanistan, Feb. 28 — NATO and American forces knew that a suicide bomber was at large in the Bagram area before the suicide bomb attack on Tuesday that killed 23 people at the main gate of the United States air base where Vice President Dick Cheney was staying, a NATO spokesman said Wednesday. But despite the vice president’s presence, the Afghan police chief in the area said he had not been informed of the possible threat.
(NYTimes)

Which is to say, things are not going well in Afghanistan.

Nor, it seems, are things going well for Spokestroop Col. Tom Collins, who gets stuck claiming the occurrence of a suicide-bomb attack at the air base where Trickshot Dick was dug in "could have been just a coincidence" and the guys who claim responsibility for it are merely "going for more psychological impact on the population," whatever that may mean, and anyway maybe the bomber was only trying to bump off the 19 hapless Afghans who were standing outside the gate, waiting to go to work.

Accompanying the Afghans were a South Korean soldier, an American soldier, and an American civilian contractor - all of whom, collectively, come in for about as much attention as a gaggle of extras on the set of "Trickshot Dick and His Excellent Breakfast." It does not pay to get too close to the Vice.