Mitch McConnell: Withdrawing from Syria is a grave mistake

Withdrawing U.S. forces from Syria is a grave strategic mistake. It will leave the American people and homeland less safe, embolden our enemies, and weaken important alliances. Sadly, the recently announced pullout risks repeating the Obama administration’s reckless withdrawal from Iraq, which facilitated the rise of the Islamic State in the first place.

Since the 9/11 terrorist attacks, I have worked with three presidential administrations to fight radical Islamist terrorism. I have distilled three principal lessons about combating this complex threat.

Lesson No. 1 is that the threat is...