The White House said Thursday that North Korea's secret work on a nuclear reactor with Syria was "a dangerous and potentially destabilizing development for the world," raising doubts about the North's intention to disclose its nuclear activities. Months after Israel bombed the reactor, the White House broke its silence and said the facility was not intended for "peaceful purposes." The disclosure comes at a critical time in U.S. nuclear diplomacy. Here's a look at what it means:

Q What is the evidence?

A CIA Director Michael Hayden, Director of National Intelligence Mike McConnell and National Security Adviser Stephen Hadley showed top members of the House intelligence committee a narrated video that included still photographs of a facility and equipment in Syria that bear a strong resemblance in design to North Korea's Yongbyon nuclear plant. Officials said the presentation did not show moving images or any North Korean workers.

Officials said the Syrian facility was within weeks or months of being completed but still needed significant testing before it could be declared operational. However, no uranium -- needed to fuel a reactor -- was evident at the site.

Q What's the intelligence community's conclusion?

A Top U.S. intelligence officials said they had high confidence in the judgment that North Korea aided Syria with its nuclear program and that the intention was to produce plutonium. But they claimed only low confidence for the conclusion that it was meant for weapons development, in part because there was no reprocessing facility at the site -- something that would be needed to extract nuclear material for use in a bomb.

Q Why release the information now? Congress has been demanding information since the Sept. 6 Israeli airstrike in Syria.

A It answers lawmakers' calls to be briefed on an important national security matter. Israel has not publicly acknowledged its role, but officials say Israel agreed to share information with the United States and signed off on its release.

The administration says it had to let some time pass after the strike, for fear that confirmation that Israel was behind the strike on Arab soil would inflame Arab-Israeli tensions or provoke warfare between Israel and Syria.

Q What was the reaction?

A Rep. Pete Hoekstra, R-Mich., and Intelligence Committee Chairman Silvestre Reyes, D-Texas, said they were angry that the Bush administration had delayed briefing the full committee for eight months. Hoekstra said, "I think it really jeopardizes any type of the agreement they may come up with" regarding North Korea.

Q Why should the world believe the White House?

A The Bush administration has a spotty record when it comes to keeping tabs on nuclear, chemical and biological weapons programs inside closed nations. In this case, it is laying out evidence both to Congress and to the United Nations nuclear watchdog agency, which will be asked to investigate.

U.S. assumptions were wrong about prewar Iraq. It scaled back its claims about Iran's nuclear program last year, adding to questions about the strength of weapons intelligence. But it was apparently right on North Korea. U.S. intelligence pegged the nation's nuclear ambitions years before Pyongyang tested a plutonium device in 2006.

Q What does it mean for the negotiations with North Korea?

A Some say it will give weight to opponents of the process, notably those aligned with Vice President Dick Cheney, by laying out a pattern of bad North Korean behavior and adding to the case that it cannot be trusted.

Others say that by documenting the North Korea-Syria link, the administration may help the talks by detailing concerns about a long history of North Korean nuclear cooperation with Syria that Pyongyang can acknowledge without specifying exactly what it is. And, by showing the world that the Syrian facility has been destroyed, the administration can say that past North Korean-Syrian cooperation is no longer a threat.

Q What does it mean for U.S. policy in the Middle East?

A Some experts fear that the disclosure of Syria's suspected nuclear intentions and the Israeli destruction of the facility might heighten Arab-Israeli tensions and could complicate efforts to mediate an Israeli-Palestinian peace deal by the end of Bush's term.

The timing overshadowed a White House meeting between Palestinian President Mahmoud Abbas and Bush, who will travel to the Middle East next month. It has also returned to the spotlight an Israeli attack on an Arab neighbor, which is likely to fan anti-Israel sentiment. At the same time, it puts Syria, and perhaps Iran, on notice that it cannot conceal a suspect clandestine nuclear facility or program without consequences.