Arms Control

American and North Korean officials traded charges Friday over the lagging effort to shut down Pyongyang's nuclear program, raising new doubts about an initiative that the Bush administration has hoped would yield a rare diplomatic success. North Korea's Foreign Ministry declared that it had fulfilled a commitment to provide U.S. officials with a full list of its nuclear activities before a Dec. 31 deadline, and intended to do no more.

The United Nations' nuclear watchdog agency says it has "serious concern" about Iran's potential to assemble a nuclear bomb because the country has not addressed questions about weapons designs, but it credited Iran for clarifying all other issues about its nuclear program history, a report released Friday says. The report by the Vienna-based International Atomic Energy Agency comes as the U.N. Security Council is considering new sanctions against Tehran. Iran has continued to defy earlier U.N.

The U.N. Security Council on Monday imposed a third round of sanctions on Iran for its refusal to halt uranium enrichment, even though some members acknowledged that more penalties were unlikely to change Tehran's mind. Key powers also offered political and economic incentives to get the country to stop enrichment and start talking again.

Vice President Dick Cheney charged in an interview released Tuesday that Iran is trying to develop weapons-grade uranium, though international inspectors and U.S. intelligence services have not found evidence of such an effort.

Shiite Muslim cleric Muqtada Sadr on Saturday rejected Iraqi government orders for his supporters to disarm, and a round-the-clock curfew in the capital was extended indefinitely as the bloody standoff between Shiite militiamen and Iraqi and U.S. forces showed no signs of abating. Militiamen on rooftops battled Iraqi soldiers and U.S. special forces in the southern city of Basra, where at least 22 "criminal fighters" were killed Saturday, the U.S. military said.

ONE OF THE least noticed and most peculiar campaign promises made by Barack Obama is his pledge, if elected president, to "secure all loose nuclear materials in the world within four years." Without doubt that is a laudable goal, but one is left wondering how exactly he expects to accomplish it in four years, or even, for that matter, in 40.

A report released Monday by the U.N.'s nuclear watchdog organization presents the clearest indication yet that Iran was working on a nuclear weapon through 2003. But there is no evidence that the weapons program continued after 2004, it says, echoing a U.S. intelligence assessment in December. The International Atomic Energy Agency said its investigation was based on questions raised by its inspections and on allegations from intelligence reports provided by the U.S. and other countries.

A senior Chinese general insisted Saturday that Beijing's military buildup was solely for self-defense, as he sought to assure a gathering of Asian defense officials that China was not seeking to dominate the region. Lt. Gen. Ma Xiaotian, the People's Liberation Army deputy chief of the general staff, pointedly said that any instability in Asia was being caused by countries seeking to expand regional military alliances and develop missile-defense systems -- a clear reference to U.S. aims in the Pacific.

President Bush on Wednesday reiterated the possibility of a military strike to thwart Iran's presumed nuclear weapons ambitions, though he also repeated that he favored a diplomatic solution. German Chancellor Angela Merkel, Bush's host in two days of meetings at a baroque castle, made clear her views: "I very clearly pin my hopes on diplomatic efforts."

The architect of Pakistan's nuclear program rejected a report alleging that his network may have shared blueprints for an advanced nuclear weapon with countries such as Iran and North Korea. The report by former top United Nations arms inspector David Albright "is all concoction, it is a pack of lies, and this is a campaign. Whenever they see Pakistan can be pressured, they pressure it," Abdul Qadeer Khan said by phone from the Islamabad villa where he is under house arrest. Khan is known as the father of Pakistan's atomic bomb.