Suicide bombing?!

The Pentagon has admitted that it appears the Mosul attack was a suicide bomber. From a press release:

WASHINGTON, Dec. 22, 2004 — It appears that a suicide bomber was responsible for the attack on the mess hall at Forward Operating Base Marez in Mosul that killed 22 people Dec. 21, the chairman of the Joint Chiefs of Staff said during a Pentagon news briefing today.
Of the 22 dead, 13 were U.S. servicemembers, five were U.S. civilian contractors, three were Iraqi security force members and one a “non-U.S. person,” Air Force Gen. Richard B. Myers said. Myers briefed the press with Defense Secretary Donald H. Rumsfeld.
A total of 69 others were wounded: 44 U.S. servicemembers, seven U.S. contractors, five Defense Department civilians, two Iraqi civilians, 10 contractors of other nationalities and one of unknown nationality and occupation. “Twenty-five of the 69 who were wounded were returned to duty,” Myers said. Others are being transported to Landstuhl Army Medical Center in Germany.
The chairman said investigators in Mosul said that at this point it “looks like it was an improvised explosive device worn by an attacker.”

Well, looks like my “lucky shot” thesis was wrong. Really wrong. I just didn’t imagine that a suicide bomber could get on a Forward Operating Base, walk into a dining hall and blow himself up.
What the hell? How the hell does this happen? He must have had help from inside, which means the Iraqis working with U.S. forces in the bases have just had their lives changed forever. Whatever bonds of trust between Iraqis working with U.S. forces have been frayed — perhaps to the breaking point.
I’m just stunned that insurgents were able to get inside and do this. This also makes the debate over whether the still-under-construction concrete dining facility was behind schedule moot. A concrete roof wouldn’t have made a whit of difference. This was an attack from inside.
How was this allowed to happen?