WASHINGTON - Russia's military offensive into Georgia has jolted the Bush administration's relationship with Moscow, senior officials said yesterday, forcing a wholesale reassessment of American dealings with Russia and jeopardizing talks on issues from halting Iran's nuclear ambitions to reducing strategic arsenals and cooperation on missile defenses.
The conflict punctuated a stark turnabout in the administration's view of Vladimir V. Putin, the president-turned-prime minister whom President Bush has repeatedly described as a trustworthy friend. Now Bush's aides complain that Russian officials have been misleading or at least evasive about Russia's intentions in Georgia.
Even as the conflict between Russia and Georgia appeared to ease yesterday, Secretary of Defense Robert M. Gates said the Russian attack had forced a fundamental rethinking of the administration's effort to forge "an ongoing and long-term strategic dialogue with Russia."
"Russia's behavior over the past week has called into question the entire premise of that dialogue and has profound implications for our security relationship going forward, both bilaterally and with NATO," Gates said at the Pentagon.
"If Russia does not step back from its aggressive posture and actions in Georgia, the U.S.-Russian relationship could be adversely affected for years to come."
The unspoken new danger is that a cooling relationship could cost the administration any hope of working closely with Russia on some of its top priorities: controlling nuclear proliferation, countering terrorism and resolving the problems of the Middle East.
If Russia and the United States rarely acted as allies in Bush's presidency, they also rarely allowed disagreements to undermine what Bush considered one of his bedrock diplomatic relationships.
After their first meeting in 2001, Bush said famously that he had looked into the eyes of Putin and "got a sense of his soul."
Bush has pursued policies that Putin vigorously opposed, including supporting the independence of Kosovo from Serbia, a Russian ally; expanding NATO to include some former Soviet-bloc nations; and stationing elements of a missile defense system in Eastern Europe.
But the two worked closely together to battle terrorism. Administration officials said that Putin generally cooperated in efforts to curtail nuclear programs in Iran and North Korea.
Only four months ago, Bush and Putin met in Sochi, the Russian resort only miles from Georgia, and signed a "framework agreement" that pledged to cooperate on a variety of diplomatic and security matters and declared that "the era in which the United States and Russia considered one another an enemy or strategic threat has ended."
Gates, along with Secretary of State Condoleezza Rice, traveled twice to Moscow in the past year for discussions on that agreement, which is now overshadowed by the war and appears unlikely to progress any time soon, if ever.
Bush has not directly addressed his relationship with Putin or his successor, President Dmitri A. Medvedev, and his aides declined yesterday to discuss his views personally.
But he has bluntly warned Russia that it risks losing its international standing.
After postponing a trip to his ranch in Texas by a day, Bush traveled to the headquarters of the Central Intelligence Agency in Langley, Va., for a briefing on the situation in Georgia.
Bush reiterated his call "for the territorial integrity of Georgia to be respected and the cease-fire agreement to be honored."
In contrast to the tough talk, Rice rushed to the former Soviet republic with a new cease-fire plan offering concessions to Moscow.
That document would allow Russian peacekeepers who were in the disputed South Ossetia region before the fighting broke to stay, and they would now be permitted to patrol in a strip up to six miles outside the area, U.S. officials said. But that allowance would be temporary, and details were still to be worked out, the officials said.
Both Georgia and Russia took steps back from open conflict yesterday, with Russia largely ending air operations over Georgia and preparing to withdraw at least some of the troops it had moved into the country, Gates said.
But the issue of Georgia's territorial integrity appeared increasingly uncertain after Medvedev met with the leaders of two separatist regions, South Ossetia and Abkhazia. His foreign minister, Sergey V. Lavrov, declared that Georgia "can forget about" reclaiming sovereignty over the regions.
Bush rescheduled his departure for Texas for today. Rice, he said, would brief him after returning from a trip to France and Georgia intended to show American support for Georgia's shaken president, Mikheil Saakashvili.
For a second day, an American C-17 cargo plane arrived in Georgia bearing relief supplies, encountering no interference from Russian forces. Bush ordered the military-run operation Wednesday, setting up what administration officials described as a direct challenge to Russia to keep its promise to allow humanitarian aid.
A small team of Pentagon officials arrived to assess how best to funnel relief supplies to those injured or displaced by the conflict.
Gates and Gen. James E. Cartwright, vice chairman of the Joint Chiefs of Staff, said at a Pentagon briefing that American forces had the right to self-defense but that he did not anticipate that they would have to resort to force to distribute the medicine and shelters.
Gates stressed that he was not predicting a return to the Cold War, and he said that over all the United States response to the crisis had been restrained.
"The United States spent 45 years working very hard to avoid a military confrontation with Russia," Gates said. "I see no reason to change that approach today."
Gates, one of the administration's experts on Soviet and Russian policies, previously served as the director of central intelligence while spending his career studying the Kremlin and its efforts to exert influence around the world.
"What happens in the days and months to come will determine the future course of U.S.-Russian relations," he said. "But by the same token, my personal view is that there needs to be some consequences for the actions that Russia has taken against a sovereign state."
The United States has already canceled outright or withdrawn from several military exercises that were to have included Russian forces in the coming days, the first concrete, punitive steps taken by the administration.
In addition, Gates said, the Defense Department "will re-examine the entire gamut of our military-to-military activities with Russia and will make changes as necessary and appropriate, depending on Russian actions in the days ahead."
The Russian government unleashed its military into Georgia to accomplish two goals, Gates said: to punish Georgia for trying to integrate with the West and to warn other nations in the former Soviet sphere of influence against closer ties with Washington and its NATO allies.
The Associated Press contributed to this article.