WASHINGTON — Russian diplomats passed detailed but sometimes inaccurate information about American troop movements to senior Iraqi officials even as U.S. troops closed in on Baghdad during the 2003 invasion, according to a Pentagon study released Friday.
The revelations, based on captured Iraqi intelligence documents, could jeopardize U.S.-Russian relations more than any single event since the end of the Cold War, analysts said. Although they cautioned that Moscow might have an explanation, the analysts said some of the details were so sensitive that they would be difficult for the government of President Vladimir V. Putin to justify.
One of the documents, which purports to be a summary of a letter sent to Saddam Hussein's office by a Russian official, claimed that Moscow had "sources inside the American Central Command in Doha," the U.S. military's headquarters in Qatar during the war.
Russia had well-known and extensive diplomatic and economic ties to Baghdad before the U.S.-led invasion and occasionally clashed with the Bush administration during the international debate over how to deal with Hussein's regime.
But the documents, made public in a study of the Iraqi military's decision-making, are the first to assert that Russia actively passed sensitive military intelligence to Baghdad during the war.
"This is one step short of firing upon us themselves with Russian equipment," said Michael O'Hanlon, a military analyst with the Brookings Institution. "It's actively aiding and abetting the enemy tactically. It's hard to get more unfriendly than that."
Press officials at the Russian Embassy did not return calls seeking comment. An official who answered the phone in the military attache's office at the embassy said he was unfamiliar with the report.
One of the most sensitive revelations, which came in a captured letter detailing Russian intelligence on American troop movements, accurately informed Baghdad that U.S. forces were massing south of a narrow passage near the southern city of Karbala.
The April 2, 2003, letter, which was reportedly passed through Moscow's ambassador to Baghdad, informed Iraqi leaders that "the heaviest concentration of troops (12,000 troops plus 1,000 vehicles) was in the vicinity of Karbala."
The Army's 3rd Infantry Division eventually captured western Baghdad after pushing through the Karbala gap just days later. Marines moved into Baghdad from the east.
Other information provided by the Russians, however, was wildly inaccurate. In a document on March 24 and again in the April 2 letter, the Iraqis were told to expect the main U.S. offensive from the western desert, including a major attack from Jordanian soil.
Kevin Wood, a retired Army officer who served as the senior researcher and chief author of the study, said he was surprised when he learned of the Russian actions. Although there was little corroboration of the contacts beyond the documents themselves, his team had no reason to doubt their authenticity, Wood said.
But Frederick Kagan, a Russia and defense expert at the American Enterprise Institute, said the actions would not be out of keeping with other efforts by Moscow to advance Iraq's cause internationally.
"We knew the Russians were opposed to the sanctions; we knew they opposed the war," Kagan said. "I'm not terribly surprised."
Analysts also said it would be important to learn whether upper levels of the Russian government were involved, adding that the signals were more likely to have come from diplomatic and intelligence agents in the region rather than from Moscow.
It also was unclear how much of the information was genuine intelligence and how much was educated guesswork.
Regardless, the revelations could undermine efforts to forge a united front against Iran's nuclear program.
"I think we have to assume that we can't trust the Russians to be impartial or even honest with us," Kagan said. "The Russians have ties with the Iranians that are also very worrying."
The 210-page report, compiled by staff at the Pentagon's Joint Forces Command after interviewing more than 100 former Iraqi officials and sifting through half a million documents, contains the most detailed accounts to date of Hussein's thinking as U.S. and coalition troops massed on his border and eventually pushed into Iraq.
It is unclear whether the Iraqi leader, who was not interviewed for the report, acted on any of the Russian information.
The authors depict Hussein as more worried about an internal coup or a repeat of the 1991 Shiite uprising in the south than he was about the coalition forces, even when they were on the outskirts of Baghdad. He continued to make tactical military decisions based on that fear until the last days of his regime.
Senior military commanders were ordered not to blow up bridges connecting Baghdad to southern Iraq so that Hussein could send loyal troops to quell any domestic opposition, even though the bridges made it easier for the Americans to advance.