When will the US start its offensive? Answer:Never.
Why? firstly its unwinnable without huge loss of life.
Also what would be the military objective apart from getting Bin Laden. It would be like the British trying to sort out Northern Ireland by bombing or invading it. Not a realistic option. This will be a spooks war with occasional Special Forces involvement, I dont see front line troops involved in any significant amount. When the yanks get Bin Laden it will be alive via some sort of diplomatic activity or dead courtesy of the SAS or similar. Another reason that they wont invade is that it has dawned on them that Bin Liner is not actually the disease but merely one of the symptoms. The real problem is that the former inhabitants of what is now Israel have never gotten over being asked to leave their own country. And unpalatable, unmentionable and inconceivable as it may seem to the Israelis, they are RIGHT to be annoyed about it. As the terrorist are unstoppable, which unfortunately is a truism, the Americans ought to stir things up as little as possible. Then the rest of us can hopefully get on with living our lives in peace while diplmatic pressure is applied to make Israel behave in a more reasonable manner towards the former (ie before 1948) inhabitants of what is now called Israel and which used to be known as Palestine.