WARSAW, Poland – President Donald Trump's lawyer, Rudy Giuliani, told USA TODAY on the sidelines of a rally here organized by an exiled Iranian opposition group that the central problem in the Middle East is Iran.

"If we don't have a peaceful, democratic Iran then no matter what we do we'll have turmoil, difficulties, problems in the Middle East. Everyone agrees that Iran is the No. 1 state sponsor of terrorism in the world. That has to tell you something: Iran is a country you can't rely on, do business with, can't trust," said Giuliani as an international conference on the Middle East kicked off in Poland's capital Wednesday.

New York's former mayor was in Warsaw to participate in a protest by the National Council of Resistance of Iran, a controversial Paris-based political organization also known as the Mujahedeen-e-Khalq, or MEK.

Giuliani has kept up many speaking engagements despite acting as Trump's attorney. He said the MEK has been a client of his for more than a decade and that he was in Poland "as a private citizen – thank God I can still do that."

Giuliani has spoken at MEK rallies before, including in Paris last year when there was a foiled bomb plot against the organization that French authorities blamed on Tehran.

Later, in an address in the rain to about 500 flag-waving MEK followers who sang revolutionary songs and held signs and large yellow balloons with messages that read "free Iran" and "Iranians want regime change," Giuliani characterized Iran's government as "assassins, they are murderers and they should be out of power."

He would not disclose whether he was being paid to attend the rally, but high-profile speakers to MEK rallies routinely get paid tens of thousands of dollars in speaking fees.

The event included speeches from several members of Poland's parliament, a former prime minister of Algeria and Robert Torricelli, a former Democratic senator from New Jersey who said he now spends most of his time developing real estate.

"As we express the abhorrence of the murder of one, so should we express the abhorrence of the murder of thousands," said Torricelli, in response to a reporter's question about why neither he nor Giuliani brought up the destabilizing Middle East activities of Saudi Arabia, and in particular its murder of Jamal Khashoggi, a columnist for The Washington Post who was killed inside the Saudi consulate in Istanbul last year.

The Trump administration has appeared willing to overlook Riyadh's human rights record – and the humanitarian disaster it has helped cause in Yemen in its military campaign against Houthi rebels – because of Washington's financial dealings with Saudi Arabia, including arms sales.

"All death is equal, and all death is becoming unequal," Torricelli added, referring to the 150,000 MEK members that the group believes Iran's government has executed. Other estimates put that death toll far lower.

The Middle East conference runs until Thursday and is jointly organized by the U.S. and Poland. The Trump administration originally said the conference would be focused on Iran, but its scope has been broadened to include the Israeli-Palestinian conflict, fighting the Islamic State, Syria and Yemen.

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Vice President Mike Pence, Secretary of State Mike Pompeo and White House adviser Jared Kushner are among the attendees, as is Israeli Prime Minister Benjamin Netanyahu and leaders from several Arab nations.

Europe's top Cabinet-level diplomats – including from France, Germany and the European Union – have not sent representatives because they disagree with Trump's "maximum pressure campaign" on Iran.

There are also concerns about what the summit will achieve. The agenda is vague and includes no concrete suggestions beyond devising "follow-on working groups."

Approximately 60 countries are being represented, but with the exception of the U.S. and Poland, many delegations feature ministers at levels lower than foreign minister.

Pompeo this week said the meeting would "deliver really good outcomes." However, Iran's government has called it a "circus" and "hostile action" and has pointed to a video released Monday by John Bolton, Trump’s national security adviser, on the 40th anniversary of the Iranian revolution.

In the video, Bolton calls Iran "the central banker of international terrorism" and accuses Tehran of pursuing nuclear weapons and missiles to deliver them and of "tyrannizing its own people and terrorizing the world." The video ends with a threat to Ayatollah Ali Khamenei, Iran’s Supreme Leader: "I don’t think you’ll have many more anniversaries to enjoy," Bolton says.

"The Warsaw conference is dead on arrival," Mohammad Javad Zarif, Iran's foreign minister, told reporters in Tehran on Wednesday. "It is another attempt by the United States to pursue an obsession with Iran that is not well-founded."

Pompeo spent Wednesday at a NATO base about 40 miles from the border of Kaliningrad, a Russian enclave on the Baltic Sea.

"Russia has grand designs of dominating Europe and reasserting its influence on the world stage," he said, while touring the area with Poland's foreign minister.

"(Russian President) Vladimir Putin seeks to splinter the NATO alliance, weaken the United States and disrupt Western democracies," Pompeo said.

Andrzej Duda, Poland's president, has floated the idea of an American military base in this Eastern European country once dominated by Soviet Union. Duda has suggested it could be called "Fort Trump."

The rally attended by Giuliani has no official connection to the ministerial meeting. But it took place just a few hundred feet away from that event.

However, complicating Giuliani's appearance at the rally is that the MEK, which sees itself as the "principal opposition to Iran's religious theocracy," is far from universally acknowledged as a constructive player when it comes to Iran.

In fact, the MEK is often described by observers of its activities, including by humanitarian groups and even a U.S. government research document from 2012, as displaying "cultlike behavior." The MEK's reported abuses – vigorously denied to USA TODAY by its senior leadership who claim they result from a vicious and protracted "disinformation campaign" by Iran's clerical rulers – range from torture and forced celibacy to holding members against their will, sometimes in solitary confinement.

"The reason Iran's regime has used such an extensive disinformation campaign against us is say to the world that there is no viable alternative to its government," said Shahin Gobadi, a Paris-based member of MEK's foreign affairs committee, who was in Warsaw.

Trita Parsi, the founder of the National Iranian American Council, a Washington, D.C.-based organization that lobbies for greater understanding between Americans and Iranians, said testimony he had heard directly from former MEK members corroborates some of the allegations against them. Two Britain-based former MEK members who defected relayed disturbing accounts to USA TODAY.

The MEK counters that its critics are often spies for the Iranian regime.

Parsi added that he believes the MEK is at least partly funded by Saudi Arabia, Iran's regional foe, a claim the MEK strongly rejects.

"The propaganda machine of Iran's government is endless," Giuliani said, addressing these accusations against the MEK. "It's ridiculous to suggest that there are people being held against their will. I've been there," he said, referring to specific claims that a facility the MEK operates in Albania has effectively brainwashed some members and refuses to let them leave the camp.

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