The reason to do it is when you want to prove that you have the power to get away with that or anything else. It’s called intimidation (aka, the Chicago Way). See also, the Overton Window.
RE: It’s called intimidation (aka, the Chicago Way). See also, the Overton Window.
Not to defend Obama here, but Bush Jr. had his share of drone strikes OUTSIDE the theater of war as well. Obama magnified the strikes ten fold.