President Trump has signed off on sending an additional 4,000 troops to Afghanistan, ahead of his address to the nation Monday night, Fox News has learned. Trump is set to unveil his strategy for Afghanistan, becoming the third commander-in-chief to attempt to stabilize the war-torn country and forge a victory in what is now America’s longest war. The speech is scheduled for 9 p.m. EDT Monday. The president will deliver the nationally televised address to troops stationed at the Army's Joint Base Myer-Henderson Hall, located next to Arlington National Cemetery.