A senior American official told reporters in Washington on Thursday night that "Once Hamas was convinced that the hostages were a burden on it and not an asset, we realized that we could move forward with a deal."He added that the commander of US Central Command had begun assembling the stabilization force, which would consist of Egyptian, Turkish, Emirati and other forces. The first command post could be set up in two and a half weeks, and 200 American fighters would help build the force on