my explanation for this - Israel has committed to step up the action. until Israel demonstrated it was willing to go all in, you can't have the western allies out there saying "hezbollah must be defeated", if israel wasn't ready to commit to do that.
I go more for the Bush "strategery" angle. The world is now littered with Dems and others who woo the day they misunderstimated Bush because they didn't pay attention. World opionion ran off in one completely wrong direction while GWB was getting his ducks in a row. What some saw as Condi's inconsistent behavior, I suspected was a decoy, a classic delaying tactic.
When will they learn that GWB doesn't give a fig what they say about him? He keeps his eye on the prize. He saw the "opportunity" side of this while everyone else was yelling "ceasefire!".