WASHINGTON — A harrowing nighttime flight over the African jungle and a wild search for a rebel leader helped forge a relationship between Democratic Sen. Bob Menendez and Republican Rep. Ed Royce, two men standing at the forefront of Congress' changing guard on foreign policy.

It was May 1997 and the lawmakers boarded a small plane to the African bush to plead with Jonas Savimbi, leader of the Angolan UNITA party, about ordering his forces to put down their arms and ending the country's civil war. Nearly 16 years later, Menendez and Royce are together again, collaborating as the new chairmen, respectively, of the Senate Foreign Relations and House Foreign Affairs committees.

They will lead a new group of foreign policy figures certain to challenge President Barack Obama on a growing list of issues: the civil war in Syria, the tenuous U.S. relationship with Pakistan, al-Qaida-linked groups in Africa and the threat from Iran's nuclear development program.