Gen. David Petraeus on the outlook for Iraq: "The situation in Iraq is, in sum, exceedingly complex and very tough. Success will take continued commitment, perseverance and sacrifice, all to make possible an opportunity for the all-important Iraqi political actions that are the key to long-term solutions to Iraq's many problems. Because we are operating in new areas and challenging elements in those areas, this effort may get harder before it gets easier. Success, in the end, will depend on Iraqi actions. As I noted during my confirmation hearing, military action is necessary but not sufficient. We can provide the Iraqis an opportunity but they will have to exploit it."

Asked whether he expects 100,000 or more U.S. troops to be in Iraq for "years to come," Petraeus said he wouldn't even "hazard" a guess. "I'm not -- I wouldn't try to truly to anticipate what levels would be some years down the road," he said. "I think that my predecessor at various times -- a number of people have noted the length of commitment that has been required in historical cases that are somewhat similar to this, although every case is absolutely unique. And the challenges here, as I mentioned, are enormous, with huge regional implications as well. It is an endeavor, again, that clearly is going to require enormous commitment and commitment over time, but beyond that time I don't want to get into try[ing] to postulate."