BEIJING (Washington Post) -- North Korea shutters its atomic reactor and is no longer making plutonium for nuclear bombs, prompting aid shipments to flow to the country that is currently struggling with shortages of electricity and food.

That happened Saturday as Pyongyang took its first step toward disarmament since the latest nuclear standoff began in late 2002. It's also exactly what happened in 1994 after the North struck a disarmament deal with the U.S. As arms negotiators gather anew this week in Beijing, Washington is wrestling with the challenge of preventing history from repeating itself -- and having another disarmament agreement end in failure. Envoys arrived Tuesday for talks on the next steps for North Korea's disarmament that Washington says it hopes will lead to disabling the nuclear facilities by the end of the year, meaning they could not be easily reactivated. After initial meetings with the North, U.S. nuclear envoy Christopher Hill expressed optimism that a timeframe for future steps could be agreed upon. ""I think we're all in the same ballpark,"" Hill said after seeing his North Korean counterpart, Kim Kye Gwan, ahead of the resumed six-nation nuclear talks Wednesday. ""We had a good discussion -- at this point there are no show stoppers."" But as Hill has noted, the reactor shutdown itself is only significant if it leads to future steps that irrevocably prevent North Korea from making more nuclear bombs. The North also shut down the reactor in 1994 after signing a deal with Washington, getting oil shipments in return and the promise of two nuclear reactors for generating electricity. Pyongyang was supposed to begin dismantling its atomic program only after the new reactors -- a type that cannot be easily used to make weapons -- were completed. But construction dragged on for years as the agreement lacked support from the U.S. Congress. Amid the stalling, the U.S. believes the North embarked on a uranium enrichment program in secret separately from its known plutonium facilities. Either plutonium or uranium can be used to make atomic bombs. In 2002, U.S. diplomats confronted the North with the alleged evidence of the uranium program and claims Pyongyang confessed, although it has never publicly done so. The U.S. halted oil shipments, leading to eventual collapse of the accord and the standoff that exists today. Washington says things are different this time