Sen. Rand Paul (R., Ky.) has named as one of his key foreign policy advisers a controversial Russia policy expert with deep ties to the Kremlin.

Dimitri Simes, the president of the Center for the National Interest, and Ambassador Richard Burt, a member of the Center’s board of directors, are recent additions to Paul’s foreign policy advisory team, the senator told National Journal earlier this year.

For years, Simes and the center have provided a sympathetic platform for the Russian government in the heart of the D.C. policy establishment. Its ties to Moscow extend throughout the organization.

The advisory council of the National Interest, the center’s chief publication, includes Alexey Pushkov, a Russian Duma official recently targeted for sanctions by the U.S. government in response to the Russian invasion of Ukraine.

Pushkov has come under fire for claiming that the Bush administration orchestrated the September 11 attacks and for blaming the 2013 Navy Yard shooting on "American exceptionalism."

A former aide to Richard Nixon, Simes is publisher of the National Interest, a hotbed of "realist" foreign policy thinking that boasts Henry Kissinger as its honorary chairman.

When contacted by the Washington Free Beacon, the Center for the National Interest denied that Simes was advising Senator Paul. Simes declined comment.

Simes’ views and connections are widely known in Russia policy circles. Last September, days after Vladimir Putin published a column in the New York Times denouncing American exceptionalism, Simes joined the Russian president on stage at the Valdai International Discussion Club forum in Russia for a televised panel discussion.

Flanked by three other panelists—Germany’s former defense minister and France and Italy’s former prime ministers—Simes seemed out of place at the high-ranking, Kremlin-sponsored forum.

"No one directly addresses Putin at Dimitri Simes’ level," noted one Washington-based Russia policy expert. "It just doesn’t happen."

Putin, in good spirits from his recent success at preventing U.S. military action against the Syrian regime, chatted with Simes about U.S. and Russia policy and quizzed his "American friend and colleague" about the U.S. budget deficit.

"I fully support President Putin’s tough stance [on Syria]," said Simes, according to the transcript released by the Kremlin.

"Not because I’m not an American patriot, but because I believe that baby talk among great powers is not the way to reach an agreement. One has to understand what to expect from the other country, and what their mettle is."

He hoped recent events would "open up a real opportunity for Russian-American relations."

The appearance with Putin "set off a lot of internal alarm bells with Russian experts," said one Russia policy specialist.

"You don’t get onstage with Putin, and sit onstage with Putin, and ask him questions in public, unless everything has been greased and unless you’re not gonna do anything that detracts from the message."

Simes has been dogged throughout his career by allegations that his work and his organizations have a pro-Kremlin slant.

After immigrating to the United States in the 1970s, Simes worked as a Russia analyst and caught the eye of Richard Nixon, who took him on as an aide.

Vladimir Kozlovsky, a Russian-born journalist who met Simes in the 1970s, said Simes often tried to play up his relationships inside the Russian government.

"I don’t think he had any knowledge of inside workings in the Kremlin [in the 1970s], but he convinced people that he did," said Kozlovsky. "People were divided. Some of them thought he was just a fake, or a Soviet agent. The rest were enamored of Dimitri."

Nixon later chose Simes to run his think tank, the Nixon Center. But Simes’ defenses of the Kremlin often dragged the Nixon Center into controversies.

The Nixon Center dropped the 37th president’s name in 2011 and became the Center for the National Interest. Sources close to the dispute say the break was due to bad blood between the Nixon family and the organization’s leadership.

Following the Putin government’s crackdown on independent Russian news outlet MediaMost in 2000, Simes mounted a vigorous defense of the Kremlin. He criticized the ousted owner of MediaMost as a corrupt oligarch who was pushing a "propaganda campaign," and hosted a meeting with one of the Kremlin-allied oil tycoons who aided the government takeover of the news outlet.

His comments prompted an angry letter from the late U.S. Ambassador to Russia Robert Strauss.

"Dear Dimitri: You ought to be ashamed of yourself," wrote Strauss in a letter on Apr. 20, 2001, as reported by the Times Union. "Irresponsible statements attributed to you … do a disservice to the new administration, the directors of The Nixon Center and many distinguished members of the American press.

"As for me personally, if you understood this country and its people a bit better, you would know the kind of personal references you make can only diminish The Nixon Center," Strauss added.

However, Simes continued to appear on MediaMost years after the government takeover.

In 2005 the Russian-American newspaper Kommersant reported that Simes had met with Kremlin allies to discuss forming a Russian-funded think tank.

The Nixon Center denied the story. Days later, the Moscow Times reported a similar account, along with claims from Kremlin adviser Gleb Pavlovsky and Russian oligarch Oleg Deripaska that they had met with Simes about the project.

Simes remained at the Nixon Center. A Kremlin-backed think tank, the Institute for Democracy and Cooperation, was formed in New York in 2008 under Putin adviser Andranik Migranyan.

"I think it was unfortunate for Mr. Simes that the Kremlin had changed its mind," said Dmitry Sidorov, who wrote the original story for Kommersant. "And the glory went to Mr. Andranik Migranyan in New York who has this Institute for Democracy and Cooperation."

The Center for the National Interest said Simes had no involvement in the development of the think tank and did not meet with Russian officials to discuss it.

"Neither the Center nor any individuals here had any part in organizing the Institute for Democracy and Cooperation," said the Center for the National Interest’s executive director Paul Saunders. "Likewise, neither the Center nor anyone at the Center discussed plans to create it with Russian officials or others."

Today, the Center for the National Interest often partners with the Institute for Democracy and Cooperation.

"The Center for the National Interest periodically arranges events with the Institute for Democracy and Cooperation as we have done with a number of other organizations in Russia across Russia's political spectrum," said Saunders. "These events have always included individuals with differing perspectives who often disagree with one another during the discussion."

Migranyan was selected to run the IDC by Russian Foreign Minister Sergey Lavrov, according to a confidential State Department cable released by WikiLeaks.

"Further boosting Migranyan’s candidacy is his well-known loyalty to the Kremlin and, especially, Putin and Medvedev, whom he describes as ‘democrats’ who support a liberal economic regime," said the cable.

Migranyan has often been given a platform both by the Center for the National Interest and in the National Interest.

Last May, the IDC and the Center for the National Interest held a joint press conference during which Migranyan defended Russia’s actions in Ukraine.

In a National Interest article last February, Migranyan said American conservatives should "recognize Putin is the same type of ‘great communicator’ that Reagan represented—a bold leader and visionary."

"I would like to turn to O’Reilly, Krauthammer, Senator McCain, Dennis Miller, and others," wrote Migranyan. "I would like to appeal to them paraphrasing Safire: ‘Gentlemen, do not be afraid to say that you love Putin, that you dream of such a leader for the United States.’

"I am confident that this will remove the heavy psychological split in which you exist," he added. "It will ease your neurosis and you will cease to poison the atmosphere of Russian-American relations.’"

Migranyan’s byline noted that he was director of the IDC but did not disclose his role as an adviser for the Putin government.

Such a pro-Putin slant extends to much of the National Interest’s editorial team, observers say.

"Although there is diversity in the dozens of articles TNI has run, its editorial staff leans heavily toward portrayal of the Kiev protests as an illegitimate coup d’état while encouraging concessions to Russia rather than a firm response to its aggression," wrote David Adesnik in National Review last March.

The Center for the National Interest does not accept money from the Russian government or other Russian entities, according to its executive director.

"The bottom line is that neither the Center for the National Interest nor The Nixon Center ever accepted contributions from the Russian government or its supporters either directly or indirectly," said Saunders.

Saunders said the Nixon Center did previously accept "relatively small" donations from a European company run by a Russian businessman "who was living in Europe after having been detained by the Russian government and losing his principal assets to a state-controlled firm."

However, he said, the organization has "not had any contact with him since that time."

The Center also denied that Simes is an adviser to Paul.

"We are aware of the reference in the National Journal but do not know more than that," said Saunders.

Saunders said Paul attended two events at the Center earlier this year, including a small discussion where Simes and others "had the opportunity to express their views."

"Indeed, we were honored to provide whatever advice we could in this way," said Saunders. "Nevertheless, we have never identified Mr. Simes as an adviser to Senator Paul."

"That overstates Mr. Simes' role," he added.

Russia consultant Tom Moore said Paul’s outreach to Simes and Burt indicates the prospective 2016 candidate is "going to some lengths, apparently, to scoop up people who aren’t associated with anything they think is ‘neoconservative.’"

Moore said this could leave Paul with limited options as he works to assemble a credible foreign policy team.

"A vast proportion of those of us who are Republicans and do foreign policy do have intellectual roots, or at least influences, that stem from neoconservatism," he said. "That doesn’t always mean dropping bombs or intervening against somebody."

Paul’s office did not respond to requests for clarification about his relationship with Simes.