An Iraqi police investigation concluded that private U.S. security guards “opened fire crazily and randomly, without any reason,” to start a shootout that killed 10 civilians last month, reported Sunday. The security firm, Blackwater USA, says its guards only returned fire from “armed enemies.”

The U.S. investigation into Blackwater’s “shoot-em-up” tactics will have to be “exhaustive and authoritative,” said the New York Daily News in an editorial. The facts aren’t all in, but Washington’s own numbers show Blackwater has been “significantly more trigger-happy” than other security contractors in the war zone. Iraqis are understandably furious. “If a large part of the job is winning over Iraqi hearts and minds, and it certainly is, punishment must be very severe, if warranted.”

If anyone is “trigger-happy,” said Ben Ryan, a former Navy SEAL, in The Wall Street Journal, it’s the journalists who are using this matter as an excuse for “smearing” Blackwater. “Security contractors make an easy target for war opponents,” but these guards are highly trained and professional, and many are veterans of elite units of the U.S. military. They help the U.S. stretch its overburdened armed forces, and “recapture its investment” in their training.

It’s quite true that “we’ve starved our armed forces,” said Ralph Peters in the New York Post, but “doling out billions” to “hired thugs” is not the way to fix the problem. “Rogue elements” among the “mercenaries” the U.S. has sent to Iraq are setting back the war effort and doing tremendous “damage to our strategic goals.”

Like it or not, said Robert D. Kaplan in The Atlantic, “the idea of a large American military presence anywhere without contractors is now unthinkable.” Without private firms running mess halls, cleaning barracks, and, yes, protecting diplomats, we would need “tens of thousands more troops” in the war zone.