The Obama administration is touting the visit of Russian President Dmitry Medvedev, who arrives in Washington on Thursday, as evidence of President Obama's success in "resetting" relations with a former Cold War rival.

But despite a new arms control agreement, diplomatic support for U.N. sanctions against Iran and an easing of tensions over U.S. resupply routes to Afghanistan, there are still major differences between the two countries.

U.S.-Russian relations were at a post-Cold War low when Mr. Obama came into office: In August 2008, Russia invaded the independent nation of Georgia, a former Soviet republic and now a U.S. ally. Moscow's pressure prompted Kyrgyzstan to end a leasing agreement with the U.S. for the Manas air base, a critical hub for resupplying troops in Afghanistan. And Russia continued to undermine international pressure on Iran and threatened to sell to that country a sophisticated air defense system known as the S-300.

"When the president took office, it was his view - and President Medvedev's view - that U.S.-Russia relations had really drifted in recent years and that we were no longer cooperating on areas of mutual interests, and that that was harming both of our interests, frankly," Benjamin Rhodes, deputy national security adviser for strategic communications, told reporters Tuesday.

Mr. Rhodes pointed to Russian cooperation on U.N. sanctions against Iran and a new agreement to resupply U.S. troops in Afghanistan as evidence that the policy of "reset" was working. He also said the new Strategic Arms Reduction Treaty, or START, signed this year but not yet ratified, was evidence that the relationship is back on track.

Nonetheless, a major U.S. concern is Russia's occupation of about 20 percent of Georgia. Michael McFaul, senior director for Russia and Central Asian Affairs at the National Security Council, told reporters Tuesday that the two leaders would argue about and discuss Russia's "occupation" of Abkhazia and South Ossetia.

"In addition to having a discussion and an argument, I would say, a disagreement about this occupation of these territories, we also have an interest in stability in the region, reducing tensions, expanding monitors, expanding transparency about what Russia is doing in these territories. And we're perfectly happy to expand their understanding of what we are doing in terms of our cooperation with the Georgian government," he said.

Moroever, at the end of the brief Russia-Georgia war in 2008, the Russians absconded with a fleet of Humvees that the U.S. military had given Georgia for training purposes. To this date, the U.S. supplies have not been returned.

David Kramer, a former assistant secretary of state for democracy, human rights and labor and a Russia expert at the German Marshall Fund, said, "The tone and tenor of the relationship are much better than they were at the end of 2008. There is a good relationship between the two presidents, but they are guilty of overselling the progress that has been made on Iran."

Mr. Kramer noted, for example, that Russia already had voted for U.N. Security Council sanctions against Iran. Its support for a fourth round of sanctions this month is overshadowed in part by Prime Minister Vladimir Putin's remarks on the day of the U.N. vote in Istanbul, where he said the sanctions would have no effect on Iran's population or leadership.

When asked about Mr. Putin's remarks, Mr. McFaul noted that Lukoil, one of Russia's largest energy concerns, recently had announced plans for divestment from Russia.

That said, Mr. McFaul said there were likely no plans to discuss Russia's ongoing contract to rebuild the Bushehr nuclear reactory in Iran since it was not covered in the U.N. sanctions. Also in a concession to Russia, the sanctions resolution does not proscribe the Russian sale of the S-300 air defense system to Iran, though the Russians have told their U.S. counterparts that they will not complete that sale.

"I don't think reset is a great success. I don't think most responsible people think it is a great success," said Dmitri Simes, president of the Nixon Center and a Russia expert. "The people in the White House who want to portray Obama as a succesful foreign policy president, may say reset is a success. But I don't think so."

"The best you can say about the reset is that it is a work in progress," he added.

Mr. Simes said he thought Russia's promise not to sell the S-300 was contingent on Congress ratifying a nuclear cooperation agreement that would offset the money Russia would lose in reneging on the S-300 contract.

Heather Hurlburt, executive director of the National Security Network, said, "The major success here 18 months in is that the relaitonship is back to a place where you can have a productive back-and-forth exchange, as opposed to where it was at the end of 2008, when basic diplomacy was not really possible."

Mr. McFaul said he was optimistic about Mr. Medvedev's plan for economic modernization. He pointed out that Mr. Medvedev visited companies in Silicon Valley on Wednesday.

On the issue of democracy and human rights, Russia in recent years has become less democratic. Major media in the country have been centralized around national energy concerns, and many observers argue that Mr. Putin, who was president before Mr. Medvedev, is the real power in Moscow.

In 2006, Russian reporter Anna Stepanovna Politkovskaya, who uncovered inhumane practices by the Russian military in its campaign in Chechnya, was murdered in her Moscow apartment building. Human rights group consider her murder unsolved and as having a chilling effect on the country's independent press.

Mr. Kramer said he would like to see human rights and democracy a higher priority for U.S. diplomacy with Russia. "I would like to see political modernization, not just economic modernization," he said.

Ms. Hurlburt said there is only so much the United States can about the nastier aspects of the Russian state.

"There are some really disappointing features of the Russian state," she said. "There are ocassionally glimmers of optimism, but Russia is an immense country, and any U.S. administration has very limited influence over its domestic politics."