A recent statement on the situation in Syria from the International Crisis Group:
Ultimately, the principal question regarding a possible military strike is whether diplomatic efforts to resolve the conflict can be reenergized in its aftermath. Smart money says they will not: in the wake of an attack they condemn as illegal and illegitimate, the regime and its allies arguably will not be in a mood to negotiate with the U.S. Carefully calibrating the strike to hurt enough to change their calculations but not enough to prompt retaliation or impede diplomacy is appealing in theory. In practice, it almost certainly is not feasible.