I had the opportunity today to question intelligence and military leaders on threats to national security.  I am greatly concerned with America's involvement in Syria, and our assistance to rebels could be used by terrorist groups that are targeting the United States.  Director of National Intelligence James Clapper confirmed to me that the Al-Nusra organization and other extremist groups operating in Syria harbor desires to attack the United States, and that these extremist groups are working with the moderate groups that the United States is assisting.   Director Clapper did not know the whereabouts of U.S. assistance that had been captured by extremists in Syria last year, nor did he know if any American aid is being utilized by terrorist groups.   I think Americans would agree that terrorist organizations with intentions of attacking the United States should not be able to access or benefit from assistance paid for by the American taxpayer.  If the administration cannot guarantee that U.S assistance in Syria is not getting into the hands of terror organizations, the assistance pipeline must be shut.