Margaret Wente in Iraq gives a pretty clear eyed view of what's happening.

Some journalists call these attacks the Iraqi resistance. That is grotesque. A resistance movement has a political objective. These killers have none. Their only goal is anarchy and chaos. And yet their tactics are politically brilliant. Although they have captured not a single military base, they've captured something much more important: newspaper headlines and prime-time television. Whatever stories the journalists have planned about the good news in Iraq (and, believe it or not, there is some) will have to wait.