Administration officials celebrate the dismantlement of the final B53 nuclear bomb in the US inventory. Retired in 1997, the Cold War-era bomb, which was about the size of a mini-van and weighed some 10,000 pounds, was carried by B-47, B-52, and B-58 bombers.
Defense experts say the drone threat represents only part of a larger, looming problem: U.S. air bases in the Pacific are increasingly vulnerable to air attacks.