Russia
Between March and September 2016, Papadopoulos made at least six requests for Trump or representatives of his campaign to meet in Russia with Russian politicians. Senator Richard Burr, the chair of the Senate Intelligence Committee, which investigated Russian interference in the 2016 United States elections, said in October 2017 that the panel was interested in Papadopoulos because he had sent e-mails attempting to set up meetings between Trump and Putin. The recipients of emails about outreach to the Russian government reportedly were Clovis, Corey Lewandowski, Manafort, Gates, representative of the Russian Ministry of Foreign Affairs Ivan Timofeev, and others.
Beginning in the spring of 2016, Papadopoulos met several times with Panos Kammenos, a Greek politician who allegedly had numerous close ties to Russian intelligence, Vladimir Putin, and the Kremlin group tasked with interfering in the 2016 United States elections. Kammenos formed the Athens-based Institute of Geopolitical Studies which in November 2014 signed a "memorandum of understanding" with the former SVR officer Leonid Reshetnikov headed the Russian Institute for Strategic Studies (RISI). In 2009, RISI, which had been an SVR operation, was placed under control of the Russian president with Reshetnikov regularly meeting with Putin and participated in Russian interference in the 2016 United States elections by developing plans of action: for example, with Russian intelligence assets and using a large disinformation campaign, Putin would support Republicans and the Trump campaign and disrupt Democrats and the Clinton campaign, and, if Trump were likely to lose the 2016 election, then Russia would shift its efforts to focus upon voter fraud in the United States in order to undermine the legitimacy of the United States electoral system and the elections. Kammenos' positions followed closely with the Kremlin's talking points.
After working on the Ben Carson 2016 presidential campaign as a foreign policy adviser, in early February 2016, Papadopoulos, later codenamed "Crossfire Typhoon" by the FBI, left the Carson campaign. That same month, he moved to London to begin working for the London Centre of International Law Practice (LCILP), with which he had been associated for several months. On March 6, he accepted an offer to work with the Trump campaign. As part of his duties with the LCILP, on March 12 he traveled to the Link Campus University in Rome to meet officials with the university.
While on this trip, he met Maltese professor Joseph Mifsud on March 14 and informed the professor about his joining the Trump campaign. On March 21, the Trump campaign told the Washington Post that Papadopoulos was one of five foreign policy advisers for the Trump campaign. Mifsud took more interest in Papadopoulos, and met him in London on March 24 with a Russian woman posing as "Putin's niece".
Mifsud traveled to Moscow in April, and upon his return he told Papadopoulos that Russian government officials were in possession of "thousands of emails" that could be politically damaging to Hillary Clinton. On May 6, Papadopoulos met Alexander Downer, the Australian High Commissioner to Britain in a London bar, and told him about the Clinton emails over drinks. This admission was important. Peter Strzok, former FBI deputy assistant director of counterintelligence, wrote:
Papadopoulos's admission predated the release of the stolen Democratic email on the website DCLeaks, and Julian Assange and WikiLeaks hadn't yet made comments about the future release of Clinton's email. None of the information about Russia's cybertheft was in the public domain. In other words, Papadopoulos had somehow learned about the hacking operation before the public did and had advance knowledge of the Russian plan to use that information to hurt Clinton's campaign. Even the FBI hadn't known about it at that time. (p. 110)
Despite his communications with members of the Trump campaign regarding Russia, the Mueller Report found no evidence that Papadopoulos ever shared information with the Trump campaign regarding Russia having "dirt" on Hillary Clinton in the form of her emails or that Russia could assist the campaign through the anonymous release of information about Clinton.
After receiving the Papadopoulos information from the Australian government, the Office of Inspector General reported that "...the initial investigative objective of Crossfire Hurricane was to determine which individuals associated with the Trump campaign may have been in a position to have received the alleged offer of assistance from Russia."(p. 59) The Senate Intelligence Committee took this to mean the Crossfire Hurricane team initially focused attention on confirming "'exactly who Papadopoulos spoke with' as 'it is implausible that Papadopoulos did not' share the offer with members of the Trump campaign."
On June 19, Sam Clovis, as Trump national campaign co-chairman, encouraged Papadopoulos to fly to Russia to meet with agents of the Russian Foreign Ministry. This occurred after Papadopoulos had been told by Joseph Mifsud that Russia had "dirt" on Clinton in the form of thousands of stolen emails that Russia wanted to share with Trump's campaign, but before there was public knowledge of the hacks of the Democratic National Committee and John Podesta's emails, the latter two hacks believed by U.S. intelligence agencies to have been carried out by Russian hackers.
On July 26, after WikiLeaks released the hacked Democratic National Committee (DNC) emails, the Australian government advised American authorities of the encounter between Downer and Papadopoulos. Receipt of this information spurred the FBI's launch of the Crossfire Hurricane investigation on July 31.
On August 10, the FBI opened a FARA case on Papadopoulos based largely upon information it received on July 26, from the Australian government originating from an Australian diplomat meeting with Papadopoulos in early May in London. The FBI counterintelligence expert Bill Priestap informed Congress in June 2018 that as there was a predicated counterintelligence operation in effect, the FBI did not spy on the Trump campaign but did investigate possible ties to Russia. British intelligence was informed of the FBI FARA case on Papadopoulos and did not halt the FBI's operation from being conducted on the soil of the United Kingdom where GCHQ could assist with the FBI in the FARA case involving Papadopoulos but the GCHQ gave no comment about its role according to a May 2, 2019, New York Times article.
After arriving in London on September 15, Papadopoulos met in a private London club with a United States citizen, FBI informer, and Cambridge professor, Stefan Halper, and a female posing as Halper's female research assistant who had invited Papadopoulos for drinks. The research assistant was an FBI investigator with the pseudonym "Azra Turk", but Papadopoulos later stated that he believed she "was CIA" with ties to "Turkish intel" and was tasked to learn about his work in the Energy Triangle which involves Cyprus-Greece-Israel, and competes with the interests of Northern Cyprus and Turkey.
As foreign policy adviser during Trump's campaign, Papadopoulos helped set up a September 23, 2016, New York meeting between Trump and Abdel Fattah el-Sisi, the Egyptian president.
In early October 2016, Papadopoulos was dismissed from the campaign following a poorly-received interview with Interfax.
On January 20, 2017, just hours before Trump was going to be inaugurated, Papadopoulos and incoming White House Chief of Staff Reince Priebus met with Greek Defense Minister Panos Kammenos. Two days later, Papadopoulos met with the head of Israel's Shomron Regional Council, Yossi Dagan, in Washington, D.C. Papadopoulos was reported to have communicated to Dagan the Trump administration's desire to work closely with Israel on the question of Israel's West Bank settlements.