The US has been quietly amassing firepower in the Pacific during a lull in tensions with North Korea, but recent developments on an under-the-radar nuclear weapon suggest preparation for a potential tactical nuclear strike. The US recently sent B-2 stealth bombers to Guam, where they joined B-1 and B-52s, the other bombers in the US’s fleet. While the B-2 and B-52 are known as the air leg of the US’s nuclear triad, as they carry nuclear-capable air-launched cruise missiles, a smaller nuclear weapon that has undergone some upgrades may lend itself to a strike on North Korea.

The B-61, a tactical nuclear gravity bomb that the B-2 can carry 16 of, has been modified in recent years to increase its accuracy and ability to hit underground targets, though that version has not yet been deployed. Not only will the B-61’s new modification make it ideal for destroying dug-in bunkers, the kind in which North Korean leader Kim Jong Un might hide during a conflict, but it has an adjustable nuclear yield that could limit harmful radioactive fallout after a nuclear attack. READ MORE