My more impetuous approach is that after Iran and Syria, there is not an open state sponsor of terror in that region. Pakistan has a problem area, but the government is playing ball with us. I think regime change in Iran and Syria would set the terrorists back big time. But it would be messy as well.
Your caution is duly noted. I think Bush has looked back on some of his "mistakes" and may have decided to correct a few.
Be Seeing You,
Chris