On Monday night, as president, Trump is expected to announce that he's sending several thousand more American troops to fight in the 16-year war.

There are currently about 8,400 U.S. soldiers stationed there, as well as approximately 6,000 from other members of NATO. The number of American troops in Afghanistan peaked at 100,000 in 2011. A total of 3,539 coalition soldiers have died during the war.

Afghanistan was barely mentioned during the 2016 presidential campaign. The GOP platform did not say much on the subject. "A Republican president will work with all regional leaders to restore mutual trust," it read. Trump said nothing about it during his convention and inaugural speeches, and essentially nothing in his campaign book, "Crippled America."