The North Korean test-firing of a mix of short- and medium-range missiles drew the anger of Japan, the United States, and other leading nations. One missile, a long-range Taepodong 2 that exploded in mid-air, caused particular concern in Washington as experts say it is designed to reach the West Coast of the United States.

Japanese Prime Minister Junichiro Koizumi visits the United States for the last time as he prepares to step down after six years in office. The visit, intended to celebrate Tokyo's close relationship with Washington, comes as North Korea's threat to launch a long-range ballistic missile raise concerns across the region.

North Korea has made threatening moves toward testing a long-range ballistic missile, prompting warnings from the United States and Japan. Some experts say it may be more productive to focus on economic engagement with Pyongyang than disarmament.

As Congress debates the U.S.-India nuclear deal, a new Council Special Report says the goal of improved relations with India can be met without sacrificing U.S. nonproliferation goals.

As the UN's nuclear agency board meets this week, it considers a new report suggesting Iran continues to defy UN wishes and has stepped up its enrichment activity even as Washington tries to work out a route to direct negotiations.

The permanent UN Security Council members and Germany agree to a package of incentives to prod Iran into giving up its nuclear activities. Yet it remains unclear if Tehran will accept the offer.

The latest signals from Iran indicate a desire for direct talks with the United States to resolve the nuclear crisis. But Washington is wary and continues to prefer multilateral pressure on Iran to freeze its uranium-enrichment program.

The Bush administration says it may take a new tack in nonproliferation negotiations with North Korea, offering a formal peace treaty as an inducement to further talks. As with many U.S.-North Korean issues, however, the details of the approach reportedly under discussion remain shrouded in nuance and laden with mutual distrust.

The White House has dismissed a letter sent by President Ahmadinejad, the first formal contact between the leaders of the U.S. and Iran in over a quarter century.

The UN Security Council has taken up a resolution that could trigger sanctions against Iran for its refusal to freeze its nuclear activities. But resistance to sanctions among some permanent members of the Security Council promises a long, diplomatic road ahead on Iran.

Iran proclaims itself "a nuclear country" after declaring it has enriched uranium to a level used in power stations. The announcement comes amid reports that U.S. policymakers are weighing the option of using military force to prevent Tehran from developing nuclear weapons.

International policymakers face a host of unattractive options in their desire to confound Iran’s nuclear ambitions, experts at a three-part CFR symposium said this week. U.S. and European diplomats insist they remain committed to negotiations, but privately sound increasingly grim about the prospects for diplomacy.

Tehran will negotiate but not renounce its right to enrich uranium, leaving policy experts divided on how to deal with the prospects of a nuclear-armed Iran.

The diplomatic stalemate over Iran’s nuclear ambitions continues, splitting experts between those who want to begin planning for a world with a nuclear-armed Iran, and those who see military action as a way of preventing it.

Nuclear terrorism and its prevention preoccupy the U.S. military, intelligence community, and diplomatic corps. But experts say the country should be doing more to lessen chances of an attack.

Diplomacy over how to handle Iran's nuclear program is stalled in the UN Security Council because of Russian and Chinese concerns that sanctions may be invoked. There are growing calls to avoid a divisive debate over sanctions and circumvent the UN by using economic levers against Iran.

The UN Security Council is trying to agree on the proper course of action toward Iran's nuclear program. Despite the myriad proposed strategies for dealing with Tehran, continued negotiations seem most likely.

As Iran prepares to face the UN Security Council, a flurry of U.S.-Russian diplomacy signals that punitive action is unlikely in Iran's immediate future.

IAEA members meeting in Vienna are expected to refer Iran to the UN Security Council after last-minute negotiations to defuse tensions over Tehran's nuclear program failed.

Talks aimed at defusing North Korea's nuclear arsenal disintegrated into name-calling after the last round ended in September. While negotiations halted, proliferation has not. So what will it take to move the process forward?