Michael Flynn’s departure as national security adviser highlights the troubling and mysterious ties between President Donald Trump and Russian President Vladimir Putin.

We know Trump is the most pro-Russia president in American history. He regularly praises Putin and dismisses well-founded charges that the Russian strongman kills innocent people. “There are a lot of killers. We have a lot of killers,” the president recently told Fox News’ Bill O’Reilly. “What, you think our country is so innocent?”

We know, too, that Putin’s intelligence agencies ran a hacking operation last year designed to hurt Hillary Clinton and help Trump. On Jan. 6, the U.S. intelligence community released a “high-confidence” report that makes untenable Trump’s repeated claims that the hacking could have been done by a random 400-pound couch potato.

What we don’t know is whether there are links between Trump and Putin. Is Trump merely an admirer of Putin’s, or does Putin actually have something on Trump that would cause the president to act in ways contrary to American interests?

Last week Flynn left his White House post after the Washington Post reported he had lied — and opened himself up to blackmail — when he denied discussing U.S. sanctions on Russia with Sergey Kislyak, the Russian ambassador to Washington, in pre-inauguration phone calls. Flynn had at least one other connection to the Kremlin, having gone to Moscow in December 2015 as a paid guest to attend a dinner alongside Putin honoring the Russian propaganda outlet RT.

The next revelation came from The New York Times: U.S. intelligence intercepted “repeated contacts” last year between Trump associates and “senior Russian intelligence officials.” There is no innocent explanation for this. It’s hardly normal for American campaign aides to be in contact with a hostile intelligence service.

Instead of explaining this troubling behavior, Trump has been fulminating against the “lying” media and their sources within the U.S. intelligence community, claiming the real story here is illegal leaks. No. The real story is Kremlingate. What did the president know, and when did he know it?

Circumstantial evidence suggests Flynn’s outreach to the Russian ambassador was approved by Trump. The widespread assumption is that Flynn was relaying a message to Putin on Dec. 29 to not worry about President Barack Obama’s imposition of sanctions to punish Russia for its meddling in our election, suggesting they would be lifted once Trump took office, perhaps as payback for the help that the Kremlin gave to Trump’s campaign. When Putin got the hint and did not retaliate, Trump tweeted Dec. 30: “Great move on delay (by V. Putin) — I always knew he was very smart!”

In another troubling development, CNN has reported that U.S. intelligence corroborated at least some parts of the 35-page dossier compiled by former British intelligence officer Christopher Steele in which he claimed Trump was subject to Kremlin blackmail on sexual and financial grounds. Although it may be impossible to embarrass Trump for sexual misdeeds after his taped confession of groping, there could well be shady financial dealings in his past that help to explain why he refuses to release his tax returns.

It is certainly curious that Trump has repeatedly denied any financial links to Russia (“I HAVE NOTHING TO DO WITH RUSSIA — NO DEALS, NO LOANS, NO NOTHING,” he tweeted on Jan. 11), and yet the public record reflects that he staged the Miss Universe pageant in Moscow in 2013 and tried to conduct numerous other deals there. His son Donald Trump Jr. bragged in 2008 that their company had “a lot of money pouring in from Russia.”

The American public deserves to know a lot more about what ties, if any, our president may have with a hostile foreign power. Media reporting is insufficient because reporters cannot subpoena documents or force testimony under penalty of perjury. The Republican-run Congress does have that authority but so far has not chosen to exercise it in any serious way. The only way we are likely ever to get to the bottom of Kremlingate is through the appointment of a bipartisan, 9/11-style commission.

It is scandalous that Republicans so far have blocked such a move. They are putting partisan considerations above the interests of the country. Will the stonewall crumble? Flynn’s resignation is not the end of the story.

Max Boot is a contributing writer to the Los Angeles Times’ opinion section and a senior fellow at the Council on Foreign Relations.

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