The debate over the leak of CIA operative Valerie Plame’s identity has caused a curious about-face by Washington politicians, with Democrats who have long favored a laissez-faire attitude toward leaks of classified information now decrying them, and Republicans who once wanted to criminalize every such leak suggesting that the one involving Ms. Plame wasn’t so terrible.

“This is just shameless,” a former Justice Department official, Bruce Fein, said. He said the political posturing on both sides may actually encourage more leaks. “It really is staggering. It undercuts their own claim that it’s serious business, because it makes people in the bureaucracy think the only issue is whether you have enough politicians lined up behind you.”

Those who track government classification policy were left spinning by last week’s political developments, as Democrats moved to take advantage of the disclosure that President Bush’s top political adviser, Karl Rove, apparently played some role as a source for news stories that exposed Ms. Plame’s employment at the CIA.

Several Democratic senators, including Senator Schumer, pushed for a new law stripping security clearances from leakers. The Senate’s Republican leadership countered with a proposal aimed at denying clearances to lawmakers who release classified FBI reports or make comments that are used as propaganda by terrorist organizations.

“It teaches us to be a little bit more skeptical of claims of national security,” said a leading authority on government secrecy, Steven Aftergood of the Federation of American Scientists. “Our classification policies are inevitably filtered through a political lens.”

Five years ago, the roles of Democrats and Republicans were essentially reversed as Congress passed a law making every leak of classified information a crime. The measure, attached to an intelligence appropriations bill, was championed by Senator Shelby, a Republican of Alabama, and supported by all the major intelligence agencies. Over the objections of those agencies, President Clinton vetoed the bill. He warned that the anti-leak measure could be used to stifle dissent.

Mr. Aftergood said that as he watched the political dynamic in Congress last week, he feared that it would again pass such a measure, which critics have compared to Britain’s Official Secrets Act. “If someone had been alert and ready to do a little political jujitsu, they might have re-enacted an anti-leak statute,” the policy analyst said. “I was holding my breath.”

Earlier this month, a New York Times reporter, Judith Miller, was jailed in connection with the criminal investigation into who leaked Ms. Plame’s identity. Mr. Aftergood said such jailings would be commonplace if the 2000 anti-leak law were resurrected. “It would just mean journalism is the shortest path to jail,” he said. “It would have been a disaster.”

Mr. Schumer, who staged three press events last week about Mr. Rove’s alleged role in the leak of Ms. Plame’s identity, is facing particular criticism for his stance. In an e-mail to reporters, Republican Party officials noted that in 1982 Mr. Schumer was one of 32 House members who voted against the Intelligence Identities Protection Act, the law at the center of the investigation that has swept up Mr. Rove and other White House officials.

A spokesman for Mr. Schumer, Israel Klein, said the senator has been consistent. “Senator Schumer, who has been a longtime advocate for whistle-blower rights, felt that the initial law that was passed was a little bit too broad,” Mr. Klein said.

Mr. Schumer also denounced the anti-leak legislation Congress passed in 2000. “We should never forget that one of the core purposes of the First Amendment was to prohibit government from suppressing embarrassing information, not criminalizing its release,” the senator said. He complained that the measure “would require all current and past government officials to guess at what might be illegal, while the threat of serious jail time hangs over their heads.”

Some conservative commentators have argued that if Mr. Rove did contribute to the disclosure of Ms. Plame’s identity, he did so unintentionally and in the context of White House efforts to shake up an entrenched bureaucracy at the CIA. However, the anti-leak measure most Republican lawmakers supported five years ago included no requirement that prosecutors prove a leaker’s intent before shipping him or her off to jail.

In another twist, the man most responsible for persuading Mr. Clinton to veto the bill with the anti-leak pro vision has emerged as a vocal critic of Mr. Rove. A former chief of staff to Mr. Clinton, John Podesta, appeared yesterday on NBC’s “Meet the Press,” to call for Mr. Rove’s ouster.

In an interview with The New York Sun, Mr. Podesta said he sees the disclosure of an agent’s identity as far more serious than most other leaks of classified information. “There’s simply something different about naming agents’ names,” he said. “I don’t think I’m splitting hairs here.”

Mr. Podesta said his main criticism of Mr. Rove is not that he violated any law, but that he may have lied about his involvement in the matter when asked by the White House press secretary, Scott McClellan.

Mr. Clinton’s impeachment has even been pulled into the debate over Mr. Rove’s conduct. Last week, the Democratic Party sent reporters a list of quotations in which Republican lawmakers call any public official who lies unfit for office. The quotes were taken from the debate surrounding Mr. Clinton’s false public statements about his relationship with a White House intern, Monica Lewsinky.

Mr. Fein, who served in the Justice Department under President Reagan, said politicians appear to be incapable of holding a consistent position on leaks. He noted that Republicans complained loudly when Mr. Clinton pardoned a former director of central intelligence, John Deutch, who was facing misdemeanor charges for mishandling classified data. Democrats were similarly up in arms when a former national security adviser to Mr. Clinton, Samuel Berger, was charged criminally for removing classified documents from the National Archives.

A Washington author who has been writing about American intelligence agencies for more than two decades, James Bamford, said he saw little consistency in the current debate.

“The Republicans have been battling for years to criminalize this, criminalize that, creating enormous secrecy. Now all of a sudden this is just business as usual?” he said. “It’s very hypocritical.”

Mr. Bamford said Democrats did little during the Clinton years to crack down on leaks. “It’s all of a sudden come up now because they’ve found a potential midterm election issue here,” he said.

no american government’s policies, democrat or republican, will change this.