The president’s swift moves underscore the confidence of an administration with a much firmer grip on the levers of government than during his first term.The last time President Trump held office, he tried to make deep cuts to foreign aid, but was blocked by Congress. He is finding little resistance from fellow Republicans this time to his move to freeze such funding.During a special counsel’s inquiry in his first term, Mr. Trump expressed a desire to fire the investigator, but White House lawyers stopped him. This term, Mr. Trump has swiftly forced out a slew of federal officials who had...