WASHINGTON — Rudolph Giuliani’s ties to Ukraine stretch back to at least 2008, when he announced that his firm was advising a former boxing champion who was running to be mayor of the capital city of Kiev.

Then, in 2017, about a year before President Donald Trump hired him to be his personal attorney, Giuliani Safety & Security began working for the city of Kharkiv in northeast Ukraine. Press releases described the firm as a consultant on Kharkiv's emergency response and security issues.

Giuliani’s emergence as a central figure in an effort to push Ukraine to investigate Trump’s potential presidential rival – a scandal that has led to an impeachment inquiry – has raised fresh questions about the former New York City mayor’s business ties and public appearances in Ukraine and other countries. One possible line of inquiry – and one that Senate Democrats have been pushing – is whether Giuliani's activities violate a federal law that requires Americans who work on behalf of foreign governments to register with the Justice Department.

This comes as the Justice Department has stepped up its use of the Foreign Agents Registration Act, or FARA, an 80-year-old law that Democrats say Giuliani may be violating. Once toothless and antiquated, the statute found its way into the public consciousness in the last two years at the height of the investigation into Russia's interference in the 2016 presidential election and has been used to prosecute several people, including two men who once were close Trump advisers.

The ramped-up enforcement has dramatically changed the landscape not only for lobbyists for foreign governments, but also for others with foreign clients: international law firms, consultants and public relations specialists who, for years, have ignored FARA, experts say.

Some don't register because of the administrative burden and the stigma of being labeled a “foreign agent,” experts say. Parties also avoid registering in order to keep relationships with foreign governments and officials secret.

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Giuliani, who did not respond to requests for comment and has hired a former Watergate prosecutor to represent him, told the Washington Post that his work for foreign governments doesn't require him to register because it doesn’t involve lobbying the U.S., and he dismissed questions about his foreign clients as "diversions by Democrats."

But legal experts say Giuliani's comments represent a misunderstanding of how broad the FARA statute is, and the Justice Department's renewed focus on enforcing it should put him on notice.

"I think at the very least, the Department of Justice would be justified in taking a very close look at the arrangements that (Giuliani) has with these foreign principals. ... Given the backdrop, given the new changes in enforcement priorities, this would seem to be a case that would be ripe for the DOJ to at least ask questions," said Josh Rosenstein, a Washington, D.C. lawyer who advises clients on FARA.

A Justice Department spokesman declined to comment.

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Ukraine ties under scrutiny

Giuliani’s business ties in Ukraine spilled into public view in September, following a whistleblower’s allegations that he was a “central figure” in an effort to pressure the country’s newly elected president into investigating former vice president Joe Biden and his son, Hunter.

House Democrats have subpoenaed records, including contracts that Giuliani and his security consulting firm had with his Ukrainian clientele. The long list of documents that the House Permanent Select Committee on Intelligence has demanded suggests a broad inquiry into possible FARA violations.

Among the documents requested pertain to “engagements, consulting, advising, or lobbying work” done by Giuliani or his firm on behalf of Ukrainian officials.

One of the Ukrainian clients that House investigators are focusing on is Pavel Fuks, a wealthy Ukrainian-Russian developer, who hired Giuliani’s firm to help improve Kharkiv's emergency services and international image. Fuks previously described Giuliani as a “lobbyist” for the city and for Ukraine.

“It is very important for me that such person as Giuliani tells people that we are a good country, that people can do business with us. That’s what we would like to bring to America’s leaders,” Fuks told the New York Times in June.

Experts say this comment should catch the attention of the Justice Department.

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“That’s precisely the type of activity that is within FARA’s scope,” said Matthew Sanderson, another Washington lawyer who advises clients on FARA. “FARA covers lobbying, but it also covers much more than that, including any effort to burnish the reputation of a foreign entity” among members of the American public.

David Laufman, a former Justice Department official who oversaw the enforcement of FARA, was more cautious, saying that if Giuliani were representing a foreign country to influence an “official action” by the United States, his actions “could come within the scope” of FARA.

Other Ukrainian officials named in the subpoena are Gennady Kernes, mayor of Kharkiv, and Vitaly Klitschko, mayor of Kiev. Giuliani advised Klitschko during Klitschko's 2008 mayoral bid. The Kiev mayor and former boxing champion visited Giuliani last July.

Giuliani's business ventures involving Eastern Europe have been guided in part by a company that boasted of doing image consulting to companies and clients with Kremlin ties. TriGlobal Strategic Ventures, a consulting firm whose website lists locations in Moscow, Kiev, New York, London, Zurich and Vienna, has a longstanding business relationship with Giuliani. Among TriGlobal's clients, according to older versions of the firm's website, was Transneft, Russia's state-owned oil pipeline giant that's subject to U.S. economic sanctions.

Simply having business ties in the form of consulting work with foreign governments is not enough to require registration under FARA, experts say. But little is publicly known about Giuliani's contracts with foreign governments. His firm, for example, had not disclosed how much it was paid for his consulting work, or what the terms of its contracts are.

“DOJ may very well want to ask questions … to get to the bottom of what the facts really are,” Rosenstein said.

Giuliani’s proximity to the president also could raise questions about whether foreign officials with whom he is connected are using the relationship to get information about U.S. policy, experts say.

“That’s arguably registrable under FARA, so you can very quickly get into troubled waters,” Sanderson said.

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Are speaking engagements covered by FARA?

Giuliani kept another side gig even after he became Trump’s personal attorney.

In October 2018, he attended a conference in Armenia, where he met with the country's acting defense minister. Two months later, he met with the king of Bahrain. In both meetings, relations with the United States were discussed, according to the two countries.

In February, he traveled to Poland, where he spoke in front of hundreds of supporters of the Mujahedeen-e-Khalq, or MEK, a controversial Iranian dissident group, and called for a regime change in Iran. Months later, he was in Albania, speaking for the same group, which the United States once labeled a terrorist organization.

These public appearances were among the several activities that merit an investigation, Senate Democrats wrote in a letter urging the Justice Department’s FARA unit to begin an inquiry.

But Laufman, who left the Justice Department in early 2018, said the types of activities the senators cited do not, on their face, violate the statute. Merely giving paid speeches to foreign groups, whether in the United States or in other countries, does not require registration – unless the speech was part of an effort to influence foreign policy and public opinion in the U.S, he said.

"There would have to be a full exploration of facts to determine whether a speech as described in and of itself would trigger an obligation to register," Laufman said.

Rosenstein said Giuliani’s ties to MEK should set off alarm bells.

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Giuliani has acknowledged that MEK has been his client for more than a decade, and he has spoken on behalf of the group during events held in Washington – which then raises questions, Rosenstein said, about whether the speech was intended to influence the American public.

Giuliani also has not said whether he was paid for the speeches, but high-profile speakers at MEK rallies routinely get paid tens of thousands of dollars.

For 50 years, the Justice Department used the FARA statute in only seven criminal cases. Laufman said that changed in 2015, when the department began a more aggressive enforcement of the law.

The number of FARA cases has more than doubled in the last two years, largely because of the prosecutions from special counsel Robert Mueller’s investigation into Russian interference in the 2016 election.

Among those who have been prosecuted are two men who were in Trump's inner circle: former national security adviser Michael Flynn, who has yet to be sentenced, and former 2016 campaign chairman Paul Manafort, who is in prison. Greg Craig, Barack Obama’s former White House counsel, was also charged; he was later acquitted.

“FARA itself and its enforcement really should no longer be viewed as sort of this sleepy old legal regime,” Rosenstein said. “And instead, you’ve seen a real awakening of the regulators.”

In Giuliani’s case, there’s a “real and present danger” that he would end up violating the law, Sanderson said.

“One contact or one act can trigger registration, so he certainly should be careful, particularly when he’s throwing stones at others,” Sanderson added.

Contributing: Kim Hjelmgaard and Kevin McCoy

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