The State Department is mainly concerned about the cables that have yet to be published or posted on Web sites  nearly 99 percent of the archive of 251,287 cables obtained by WikiLeaks. With cables continuing to trickle out, they said, protecting those identified will be a complex, delicate and long-term undertaking. The State Department said it had combed through a majority of the quarter-million cables and distributed many to embassies for review by diplomats there.

“We feel responsible for doing everything possible to protect these people,” said Michael H. Posner, the assistant secretary of state for democracy, human rights and labor, who is overseeing the effort. “We’re taking it extremely seriously.”

Contrary to the administration’s initial fears, the fallout from the cables on the diplomatic corps itself has been manageable. The most visible casualty so far could be Gene A. Cretz, the ambassador to Libya, who was recalled from his post last month after his name appeared on a cable describing peculiar personal habits of the Libyan leader, Col. Muammar el-Qaddafi. While no decision has been made on Mr. Cretz’s future, officials said he was unlikely to return to Tripoli. In addition, one midlevel diplomat has been moved from his post in an undisclosed country.

But other senior diplomats initially considered at risk  for example, the ambassador to Russia, John R. Beyrle, whose name was on cables critical of Prime Minister Vladimir V. Putin  appeared to have weathered the disclosures.

There is anecdotal evidence that the disclosure of the cables has chilled daily contacts between human rights activists and diplomats. An American diplomat in Central Asia said recently that one Iranian contact, who met him on periodic trips outside Iran, told him he would no longer speak to him. Sarah Holewinski, executive director of the Campaign for Innocent Victims in Conflict, said people in Afghanistan and Pakistan had become more reluctant to speak to human rights investigators for fear that what they said might be made public.