With questions still looming over the deaths of U.S. troops in Niger, the ranking member of the Senate Foreign Relations Committee faced top Trump administration officials last week in a public hearing and warned of a “global, endless shadow war” against terror groups.

Sen. Ben Cardin’s comments to Defense Secretary Jim Mattis and Secretary of State Rex Tillerson were part of the new political battle over President Trump’s authority to target a growing roster of extremists aligned with the Islamic State and al Qaeda across Africa and the Middle East.