Need proof that the "surge" is working? Gen. David Petraeus has this to offer: The bad guys are starting to kill Americans rather than Iraqis.

On "Fox News Sunday" yesterday, Chris Wallace asked Petraeus about last week's Pentagon report on Iraq -- the one that said that the "overall level of violence" remained unchanged during the first several months of the "surge."

"General," Wallace asked, "why shouldn't we back home view that as disappointing?"

Petraeus' response: "Well, the aggregate level is about the same. We actually have borne the brunt of much more of that, as have Iraqi security forces, and civilians a good bit less.

"In fact, one of the metrics that we track, which is sectarian murders and executions in Baghdad, went down ... by the end of April, it was down to about a third of where it was back in January.

"It did come back up as we announced in the month of May a little less than half. That is trending back down again.

"The fact is that as we go on the offensive, the enemy is going to respond. That is what has happened. Car bombs have been coming steadily down. And as I mentioned, sectarian executions in Baghdad in particular have come down.

"So again, certainly it is a mix, and that is what I've tried to convey with my assessment, that we're ahead in some areas and we need to do some serious work in others."