Terrorist safe havens have proliferated around the world. The 9/11 commission's No. 1 recommendation was to use all elements of National power to deny sanctuary to terrorist groups. Yet we have seen safe havens spread with alarming speed in recent years. Such territory makes it far easier for terrorist groups to train recruits and hatch plots against the West. During this administration, no less than three extremist sanctuaries have emerged or expanded in Syria, Iraq, and Libya. In Afghanistan, if the administration goes forward with the plan to withdraw our troops like they did in Iraq, we might see terrorists reclaiming the territory from which they planned 9/11. Despite U.S. strikes against the group, ISIS still holds onto thousands of square miles of territory where they are able to operate their terrorist army. Recent estimates indicate that they may have up to 30,000 fighters, of which 2,000 or so are Americans and Europeans. These radicalized Westerners represent an exceptionally grave threat to the U.S. homeland because of their militant training, extremist connections, ease of travel, and intimate knowledge of the West.