NEW : The Justice Departments ' Office of Legal Affairs provides the president with a preliminary legal opinion . Trump 's plan to invade Syria is not legal under international law , they say . Congressional approval would lend it some legitimacy , an administration official says . Others briefed on the administration 's plan say it is too broad .
NEW : The Justice Departments ' Office of Legal Counsel provides the president with a preliminary legal opinion . Obama 's plan to strike Syria is not legal under international law , experts say . Congressional approval would lend it some legitimacy , an administration official says . Lawmakers briefed on the administration 's proposal say it is too broad .