1. President Trump made a surprise visit to U.S. troops in Iraq.

It was his first visit to troops stationed abroad in a combat zone.

The trip, shrouded in secrecy, came in the midst of a partial government shutdown and less than a week after Mr. Trump announced plans to withdraw all troops from Syria and about half of those stationed in Afghanistan.

The president’s decision on Syria led to the resignation of his defense secretary, Jim Mattis.

Mr. Trump told reporters on the ground at Joint Base al Asad that he had no plans to withdraw troops from Iraq. Instead, he said, the U.S. may use Iraq as a military base to carry out operations on Syria and fight the Islamic State.