Corker butted heads with Obama as chief of Senate Foreign Relations Committee

Senate Foreign Relations Committee, Chairman Sen. Bob Corker, R-Tenn., center, flanked by the committee's ranking member Sen. Robert Menendez, D-NJ., right, and Sen. James Risch, R-Idaho, listens on Capitol Hill in Washington, Wednesday, March 11, 2015, as Secretary of State John Kerry, center, back to camera, testifies. Three of America's top national security officials face questions on Capitol Hill about new war powers being drafted to fight Islamic State militants, Iran's sphere of influence and hotspots across the Mideast. (AP Photo/Pablo Martinez Monsivais)
photo Senate Foreign Relations Committee Chairman Sen. Bob Corker, R-Tenn., right, talks with Sen. Susan Collins, R-Maine, a member of the Intelligence Committee, as they walk together on Capitol Hill in Washington, Tuesday, Dec. 15, 2015, as senators gather for weekly party caucuses as White House and congressional negotiators move toward clinching a tax and spending compromise that would cap Congress' year by extending numerous tax credits and financing government agencies in 2016. Differences still remain in the end-of-the-year negotiations and Capitol Hill leaders may need another short stopgap before striking a final agreement. (AP Photo/J. Scott Applewhite)

WASHINGTON - From Iran to Syria to Africa, U.S. Sen. Bob Corker, R-Tennessee, was often at the center of national and international issues during his first year as chairman of the Senate Foreign Relations Committee.