Donald Trump’s seeming admiration for Vladimir Putin—whether real or imagined, reciprocal or unilateral—has spawned much speculation. The story dates back at least to 2013, when, ahead of the Miss Universe pageant he had brought to Moscow, Trump wondered if the Russian president would show up and “become my new best friend.” As president, amid mounting talk of possible collusion between his campaign and Russia, Trump has tried to distance himself from Putin—backtracking on earlier claims that they’d spoken “directly” and had a “relationship”—but the two leaders’ much-longer-than-planned July meeting in Germany and the bonhomie that followed suggest that the U.S. president’s positive feelings for Putin have endured.

So how to explain this apparent affection? We submit eight hypotheses, with the caveat that no single explanation will likely suffice and that a combination of the factors outlined below might be at play. And we’re asking readers to weigh in: Which do you think is the most plausible? Or perhaps you have your own theory? If so, select “Other” and explain in the comments.

Hypothesis 1: The Kissinger worldview. Trump’s affinity for Putin may be based on the pragmatic recognition that good relations with Russia are important to advancing a number of vital U.S. interests, not least of them counter-terrorism, non-proliferation and avoiding a nuclear war. Trump shares the viewpoint of Henry Kissinger, who has cast Russia as America’s “Siamese twin” in maintaining a semblance of world order. Here’s some direct evidence:

• Trump has met with Kissinger on several occasions to seek advice; Putin regularly meets with Kissinger for informal discussions with a view to have his points relayed to policymakers in the U.S. (See our collection of Kissinger’s insights and recommendations on Russia.) In his public statements, Trump has suggested that good relations with Putin’s Russia are a matter of realpolitik:
  • “Folks, we have perhaps the second most powerful nuclear country in the world. If you don't have dialogue, you have to be fools,” he said. (CNN, 07.13.17, Reuters, 07.13.17)
  • “Wouldn't it be nice if we got along with the world, and maybe Russia could help us in our quest to get rid of ISIS?” (New York Times, 03.04.16)
  • U.S. Senators John McCain and Lindsey Graham—who consider Russia a major threat—“should focus their energies on ISIS, illegal immigration and border security instead of always looking to start World War III.” (Politico, 01.29.17)

Hypothesis 2: Admiration for strong leaders. Putin’s management style—that of an unrestricted, sole decision-maker—comes close to that of a powerful business executive, an approach Trump prides himself on bringing to the management of the country. Trump may have a predisposition for strong leaders who can make difficult decisions and execute them, overriding dissent and avoiding the continuous weighing of pros and cons, as exemplified, in Trump’s view, by former President Barack Obama. Here’s some direct evidence:

• Trump has repeatedly praised Putin’s strong leadership, during and after his presidential campaign. (See our collection of Trump’s comments on Putin.) During a Republican presidential debate, Trump said: “I think Putin has been a very strong leader for Russia. I think he has been a lot stronger than our leader, that I can tell you. … I don’t say that in a good way or a bad way. I say it as a fact.” (CNN, 03.15.16)
• Trump said of Putin during a town hall ahead of the election: “The man has very strong control over a country. Now, it's a very different system, and I don't happen to like the system. But certainly, in that system, he's been a leader, far more than our president has been a leader.” (Washington Post, 09.07.16)
• Trump continued to draw a distinction between Putin and Obama after he took office. “For eight years Russia 'ran over' President Obama, got stronger and stronger, picked-off Crimea and added missiles. Weak!” Trump tweeted. (Twitter, 03.07.17)

Hypothesis 3: Respect for Russia’s history of resilience and strength. Trump might be admiring not just Putin personally but Russians’ role in history, as fighters against Napoleon, Hitler and Genghis Kahn. Trump respects Putin for his effort to rebuild the military strength of Russia and recapture some of the glory of the Russian Empire.

• Direct evidence: Speaking about the historical reputation of the Russian military, Trump said: “The Russians have great fighters in the cold. They use the cold to their advantage. I mean, they’ve won five wars where the armies that went against them froze to death. … It’s pretty amazing.” (New York Times, 07.19.17)
• Circumstantial evidence: Shortly after Russia’s 2014 annexation of Crimea, which drew international condemnation, Trump tweeted: “I believe Putin will continue to re-build the Russian Empire. He has zero respect for Obama or the U.S.!” (Twitter, 03.21.14)
• Big “but”: At the same time, Trump is not known for his appreciation for or mastery of history. He reportedly has a short attention span and little interest in reading. He also stirred up a great deal of criticism from historians with comments he made this spring about the Civil War and Andrew Jackson. (CNN, 05.22.17)

Hypothesis 4: Cultural affinity for Russians. Trump might feel a cultural affinity for Russians in general. If true, this likely has less to do with Pushkin and Prokofiev than with certain common traits of Americans and Russians. Both share a kind of “W­ild West” mentality, having conquered large swaths of territory, and their citizens have a reputation for being resourceful, assertive or even brash, often too much so for the taste of Western Europeans. Here’s some circumstantial evidence:

• In October 2013, Trump told “Late Show” host David Letterman: “I’ve done a lot of business with the Russians. They’re smart and they’re tough and they’re not looking so dumb right now… He’s a tough guy, Putin.” (YouTube, 10.22.13)
• In February 2014, Trump said on “Fox and Friends”: “When I went to Russia with the Miss Universe pageant, [Putin] contacted me and was so nice. I mean, the Russian people were so fantastic to us… I’ll just say this, they are doing—they’re outsmarting us at many turns, as we all understand. I mean, their leaders are, whether you call them smarter or more cunning or whatever, but they’re outsmarting us.” (Archive.org, 02.014.17)
• Anthony Scaramucci, a financier and ardent Trump backer who would briefly serve as the president’s communications director, said that Western sanctions against Russia had backfired “in some ways … because of Russian culture. I think the Russians would eat snow if they had to.” (Newsweek, 07.21.17)

Hypothesis 5: He’s a contrarian. Perhaps Trump, who has shown a willingness to buck conventional wisdom and court controversy for the sake of publicity, isn’t really enamored of Putin. Rather, he has expressed admiration for him precisely because others in the West lambasted him after the Ukrainian crisis erupted. He might have even changed his opinion of Putin, whatever it really was, but clung to his public views feeling some sort of pressure to remain consistent. Here’s some circumstantial evidence:

• Trump has expressed other views related to Russia that are highly unorthodox, especially in Republican circles. In 2013, Trump sided with Putin after he took issue with then-President Obama’s use of the term “American exceptionalism”: “You think of the term as being fine, but all of sudden you say, what if you’re in Germany or Japan or any one of 100 different countries? You’re not going to like that term,” Trump told CNN. “It’s very insulting and Putin really put it to him [Obama] about that.” (BuzzFeed, 08.01.16)
• In response to the claim that Putin is a “killer,” Trump said: “There are a lot of killers. Do you think our country is so innocent?” (CNN, 02.06.17)
• Ahead of the vote in Congress in late July for a new set of sanctions against Russia, his then-communications director Anthony Scaramucci said that Trump “may sign the sanctions exactly the way they are, or he may veto the sanctions and negotiate an even tougher deal against the Russians.” He cited Trump’s “counterintuitive, counterpunching personality” to explain why the president is considering a veto. (AP, 07.27.17)

Hypothesis 6: Ideological affinity. Trump (or, rather, some of his advisors) might admire the conservative values that Putin has been championing and that the West has been gradually losing. Both leaders have stressed the importance of faith and cultivated ties with religious groups, the Russian Orthodox Church in Putin’s case and conservative Christian groups in Trump’s. Here’s some circumstantial evidence:

• Trump hired as his chief advisor Steve Bannon, an outspoken critic of Western liberalism. Bannon has stated that the greatest mistake the baby boomers made was to reject the traditional “Judeo-Christian” values of their parents. In a 2014 talk at the Vatican, Bannon made it clear that Putin was “playing very strongly to U.S. social conservatives about his message about more traditional values.” As a recent Atlantic essay argued, Putin has realized that “large patches of the West despised feminism and the gay-rights movement,” and he has transformed himself into the “New World Leader of Conservatism,” whose traditionalism offers an alternative to the libertine West that has long shunned him. (The Atlantic, 03.27.17)
• Trump has himself staked out such positions. In a July 2017 speech in Warsaw (which was believed to have been heavily influenced by Bannon), Trump declared: “The people of Poland, the people of America and the people of Europe still cry out ‘We want God.’” (New York Times, 07.11.17, The White House, 07.06.17)
• While Trump signaled support for LGBT rights during his campaign, he recently announced, in a stark reversal from a policy instituted by former President Obama, that trans-gender people would be banned from the military. The move was one of several that antagonized gay-rights groups. (CNN, 06.13.16, New York Times, 07.27.17)

Hypothesis 7: Financial gain. Trump might view a good relationship with Putin as a way to further expand his business empire. In this way, Trump’s approach to Putin represents a continuation of efforts dating back to the late 1980s to build relationships with powerful Russian government and business leaders. Here’s some circumstantial evidence:

• Trump wrote in his 1987 book “Art of the Deal” that he was interested in partnering with the Soviet government to build a luxury hotel in Moscow, and he planned to give then-Soviet leader Mikhail Gorbachev a tour of Trump Tower in 1988. (The Washington Post, 12.03.88)
• The Trump family and its businesses have reportedly long pursued Russian investors and deals in Russia and former Soviet republics. In 2008, Donald Trump Jr. told a real estate conference that he had been averaging a trip to Russia about every three months for the past year and a half, but suggested that the Trump Organization, the family business, didn’t have the adequate connections to safeguard investments: “It is definitely not an issue of being able to find a deal—but an issue of ‘Will I ever see my money back out of that deal or can I actually trust the person I am doing the deal with?’ As much as we want to take our business over there, Russia is just a different world. … [I]t is a question of who knows who, whose brother is paying off who, etc.” He added: “Russians make up a pretty disproportionate cross section of a lot of our assets. … We see a lot of money pouring in from Russia.” (New Republic, 07.13.17, New York Magazine, 07.11.17, McClatchy, 06.28.17, USA Today, 02.15.17, The Daily Beast, 01.11.17)
• Unlike past presidents, Trump has refused to place his business holdings and investments into a blind trust; he has instead placed them in a “revocable trust,” controlled by his adult sons, and the president was able, as of April, “to withdraw profits and underlying assets from his trust at any time.” (CNBC, 06.12.17, BBC, 04.18.17, ProPublica, 04.04.17, Politico, 01.11.17)

Hypothesis 8: Russia has compromising materials on him. Trump may feel compelled to stay on Putin’s good side because the Russians might have kompromat—compromising materials—on him. The existence of kompromat was a central claim in the so-called Steele dossier, compiled by former British intelligence agent Christopher Steele as part of opposition research against Trump during the 2016 campaign. The document alleges that the Kremlin had been “cultivating, supporting and assisting” Trump for at least five years and amassed a file on him that includes videos of him engaged in lurid sexual activities. Here’s some speculative, uncorroborated evidence:

• The Steele report alleges that there was an “extensive conspiracy” between the Trump campaign and the Kremlin that was “sanctioned at the highest levels.” If there were contacts between the campaign and Russian officials that have not been revealed, this may give the Kremlin some leverage over Trump. All sources in the Steele report are anonymous, and only a few of its claims have been independently confirmed since it surfaced publicly in early 2017. However, the FBI is investigating allegations of collusion under the oversight of an independent special counsel. The supposedly compromising materials against Hillary Clinton that were promised to Donald Trump Jr. ahead of his controversial June 2016 meeting with a Russian lawyer allegedly came from Russia’s prosecutor general, who has been described as a master of kompromat. (Steele report, Jan. 2017, New York Times, 07.17.17)
• Citing three sources, the Steele report describes a specific sexual encounter involving Trump and multiple women in a suite at the Ritz Carlton Hotel in 2013. But like all sources in the report, these are anonymous, and there’s been no independent confirmation of the incident or other sexual allegations. Moreover, the negligible damage to Trump’s presidential aspirations done by the “Access Hollywood” scandal casts some doubt on the idea that such kompromat would give the Kremlin sway over him. (Steele report, Jan. 2017)
• Media reports have said that Trump owes much of his wealth to “a flow of highly suspicious money from Russia,” including millions in illicitly gained funds. As the New Republic recently reported, “To date, no one has documented that Trump was even aware of any suspicious entanglements in his far-flung businesses, let alone that he was directly compromised by the Russian mafia or the corrupt oligarchs who are closely allied with the Kremlin. So far, when it comes to Trump’s ties to Russia, there is no smoking gun.” This, of course, raises the question: Might the Russian government have one?

The opinions expressed in this commentary are solely those of the author.