North Korea Warned

Yonhap/Associated Press

A U.S. Air Force B-2 stealth bomber flew near Osan U.S. Air Base, south of Seoul, on Thursday in a display of force aimed at deterring North Korean threats of attacks on the U.S. and South Korea.

Two B-2 stealth bombers flew from a base in the American heartland, dropped test charges on targets near North Korea and returned to the U.S. on Thursday, as Washington mounted its most overt display of military force amid months of escalating tensions with North Korea.

The B-2s, the most advanced heavy bombers in the U.S. arsenal, flew low over the South Korean city of Osan before dropping eight dummy munitions on a South Korean bombing range as part of annual joint exercises with South Korea's military. The dummies were inert versions of 2,000-pound bombs, one of the bigger conventional weapons in the U.S. arsenal. The B-2 can also carry nuclear payloads.

The maneuvers illustrated the growing concern inside the Obama administration that North Korea and its 30-year-old leader, Kim Jong Eun, may move beyond threats that have been commonplace against the U.S., South Korea and other allies in Asia. The fear is that Mr. Kim will continue with a string of military provocations that run the risk of sparking a major security crisis in Northeast Asia.

In North Korea, Mr. Kim ordered rockets to be on standby to strike U.S. bases in South Korea and the Pacific, as well as the U.S. mainland, state media reported. The order came after Mr. Kim and senior military officials held an emergency meeting in the early hours Friday, according North Korea's official KCNA agency.

The B-2 flights were "an ultimatum that [the U.S.] will ignite a nuclear war at any cost on the Korean Peninsula," Mr. Kim said at the meeting. KCNA said the leader "said he has judged the time has come to settle accounts with the U.S. imperialists in view of the prevailing situation."

Tensions Escalate

North Korea Cuts Hotline North Korea said it was severing a military hot line with South Korea and showered invective on Seoul's new leader, even as Seoul pursued plans to improve relations with the North.

Signal Amid the Noise The hotine is used to coordinate traffic heading from the South into the Kaesong Industrial Complex, a few miles inside the North. So far, traffic heading from the South into the industrial zone has been unaffected.

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