The answer appears to be a strikingly broad legal argument to strike virtually anywhere—without Congressional say-so.
Secretary of State Rex Tillerson informed a senator in a recently-revealed letter that President Trump considers himself to possess inherent constitutional authority to launch military action without any act of Congress, a sweeping assertion that appears to resurrect from the early George W. Bush years the most imperial notions of the presidency.
Now a group comprised mostly of former Obama administration attorneys is suing to force disclosure of a seven-page Justice Department document they believe codifies the broad legal claim. As they await a judge’s verdict, they believe the secret opinion they seek provides a blueprint for the presidency to put the final nail in the long-constructed coffin for Congress’ own constitutional authority over American war.
Last April, Senator Tim Kaine watched Trump launch a cruise-missile fusillade against a Syrian airbase firmly under the control of regime dictator Bashar Assad. Trump publicly justified attacking the airbase as a means to impose costs on Assad for his chemical weapons attack.