At the Manama Dialogue last weekend, Tom Barrack, the US ambassador to Turkey and a longtime Trump confidant who has emerged as one of Washington's most active voices on post-Assad Syria, delivered a message that Damascus heard as both promise and ultimatum: "There is no Plan B for Syria, only integration."The remark, delivered to a Gulf audience still adjusting to the speed of Bashar Assad's December collapse, exposed a contest over who will define Syria's re-entry into the regional order. On