Jun 16, 2014 — Iran and six world powers have set a July 20 deadline for reaching a deal on Iran's nuclear program. With the clock ticking, here's a look at the main obstacles.
Apr 29, 2014 — The exercises, while not uncommon, are considered provocative in the immediate wake of President Obama's visit to South Korea.
Apr 24, 2014 — The Marshall Islands, the site of 66 U.S. nuclear weapons tests between 1946 and 1958, says the Non-Proliferation Treaty requires nuclear states to disarm.
Mar 24, 2014 — Tokyo had long maintained the cache of highly enriched uranium and weapons-grade plutonium for research purposes. The deal is a major nonproliferation victory for the White House.
Jan 20, 2014 — Inspectors from the International Atomic Energy Agency report that Tehran has halted the highest level of uranium enrichment, a key part of the sanctions deal reached earlier this month.
Oct 8, 2013 — South Korean officials say they have confirmed the North has restarted a nuclear reactor that had been shut down in 2007. In April, North Korea said it would restart the reactor to supply its nuclear weapons program.
Feb 15, 2013 — The fallout from Cold War bomb tests is shedding light on why the Achilles tendon heals so poorly after injuries. By looking at carbon-14, scientists have found that tendon tissue in people who were alive during the tests hasn't changed much since they were youngsters.
Jan 23, 2013 — The threat follows the U.N. Security Council's condemnation Tuesday of North Korea's rocket launch in December. A U.S. official in Seoul said any such step by Pyongyang would be a "mistake."
Oct 15, 2007 — What did Israel bomb, and why?