With national security advisor Michael Flynn’s resignation and new reporting from The New York Times that Trump campaign officials had repeated contacts with senior Russian intelligence officials, it is time to ask the fundamental question about this administration’s underlying weakness over Russia:

Was there a quid pro quo between the Kremlin and the Trump campaign to help Trump win?

No one wants to believe this, of course, and it is an important moment to give Trump as many benefits of the doubt as possible. It is probably true that Trump would have defeated Hillary Clinton without any Russian cyber-shenanigans (though of course Richard Nixon would have easily defeated George McGovern in 1972 without ordering a break-in at the Watergate Hotel). It is also true that the leaks coming from the intelligence community could represent a serious threat to civil liberties, though it is not clear to me whether this information is coming directly from the intelligence community or secondhand from any number of potential investigations. There are many ‘known unknowns’ here, and there are potentially even more ‘unknown unknowns.’

But here is what we think that we know, as of February 15:

1. US president Donald Trump has a weird relationship with Russia and with Russian president Vladimir Putin. Maybe he’s just ‘odd,’ maybe there’s some mutual ‘alpha-male’ admiration, maybe the Kremlin has some dirt on Trump, politically or financially. Who knows! No one has access to Trump’s tax returns, so we don’t know if, say, Trump is in deep debt to Russian lenders. It goes back to before Trump’s campaign (recall that weird Tweet from 2013 about the Miss Universe pageant). Forget the more salacious parts of that dossier, and even put aside everything in that dossier as hearsay. There are real questions about conflicts of interest because Trump has violated the financial disclosure norms that have dominated presidential politics for decades.

2. Assume the best-case scenario for Trump — his fondness for Russia/Putin is just idiosyncratic. He is a very idiosyncratic president, it’s true! Nevertheless, he was clearly the most pro-Russian presidential candidate since Henry Wallace in 1948, and it is a posture that makes both Democrats and most Republicans uncomfortable. Trump’s baseline position on NATO (it’s obsolete and ‘free loaders should pay more’) isn’t so different from the Obama position, but Trump’s language clearly gave a lot of comfort to Moscow. It’s worth noting that the only time the Trump campaign intervened with the RNC platform last July was to weaken language about protecting Ukraine.

3. You don’t have to agree with Mitt Romney’s 2012 statement that Russia is America’s top geopolitical threat to realize that Russia isn’t quite at the top of anyone’s list of American allies.

4. During the campaign, Trump was willing to cut ties to Paul Manafort when details emerged about Manafort accepting murky payments from Putin-backed Viktor Yanukovych, then Ukraine’s president and a Manafort client. But Trump kept Manafort on the payroll for months, even as Manafort’s uncomfortable role in Ukraine and elsewhere was public record. It has emerged from the New York Times report that Manafort was one of the Trump campaign officials in contact with Russian officials, though Manafort pushed back in very strong terms that he committed any impropriety:

Mr. Manafort, who has not been charged with any crimes, dismissed the officials’ accounts in a telephone interview on Tuesday. “This is absurd,” he said. “I have no idea what this is referring to. I have never knowingly spoken to Russian intelligence officers, and I have never been involved with anything to do with the Russian government or the Putin administration or any other issues under investigation today.”

He added, “It’s not like these people wear badges that say, ‘I’m a Russian intelligence officer.’”

5. Flynn, among other top Trump officials, views Russia as the lesser of two evils in a greater struggle between ‘Western civilization’ and ‘radical Islam.’ You can disagree with that approach, but it’s not so incredibly different from the viewpoint of the Bush administration after the 2001 terrorist attacks, which was silent about Putin’s power grabs (recall Putin’s unilateral decision in 2004 to end elections for state governors) in the name of defeating terrorism.

6. The incoming Trump administration wanted to re-evaluate bilateral ties with Russia. Bush, who famously ‘looked into Putin’s eyes’ and ‘saw his soul’ and Obama, whose administration famously tried to hit ‘reset’ with Putin and then-president Dmitri Medvedev, felt the same way. Trump’s statements about Russia have been inartful from the outset, but that’s true about a lot of the things Trump says — he’s an outsider, not a polished politician, and that was his appeal. But the underlying idea of a reset isn’t on-its-face idiotic, and both Bush and Obama tried to do the same. Moreover, the Obama administration worked with Russia on nuclear disarmament, Syrian chemical weapons and the Iran energy deal. If Trump’s language was eccentric, the concept of working with Russia is not.

7. The Trump transition team made no bones about stepping on the Obama administration’s toes after November 9. Remember the Taiwan brouhaha? South China Sea sable-rattling? Floating Nigel Farage as the next UK ambassador? The public grumbling about that UN vote on Israeli settlements? The meeting in Trump Tower with Japanese prime minister Shinzo Abe? It’s not surprising that Flynn and Trump would be doing the same thing about Russia. It would not be out of line with everything else Trump was doing in plain sight.

8. Throughout the campaign, it was increasingly clear to government and intelligence officials that Russia was up to dirty tricks to the benefit of the Trump campaign. Obama didn’t do anything about it, because he thought (like everyone else) Clinton would win, and he didn’t want to rock the boat domestically or internationally. That was probably a miscalculation. But it should have been clear then, and it is certainly clear now, that Russia tried to tip the scales against Clinton. It’s important for Democrats to acknowledge that Clinton ran a horrible campaign, and it is not clear that, barring Russian interference, she would have won 100,000 or so votes in the Rust Belt.

9. Trump at one point last July even invited Russia to hack into Clinton’s emails. Of course, that’s exactly what most officials now acknowledge that Russian hackers did — both in terms of hacking the DNC and Podesta. Giving Trump the benefit of the doubt, this may have just been ‘Trump being Trump.’ It was probably a joke, so giving him the benefit of the doubt, set that aside as campaign foolishness (just like when Trump said he could walk down Fifth Avenue in Manhattan shooting people and not lose voters).

10. We still do not know if there was a quid pro quo between the Kremlin and the Trump campaign. The latest reporting shows a lot of smoke (and no fire — yet), but we do know there were plenty of conduits, It wasn’t just Manafort and Flynn, but possibly one-time Trump campaign adviser Carter Page and/or Trump attorney Michael Cohen.

11. Russia is working to influence election outcomes all across Europe in 2017 — The Netherlands, France, Germany. We know, further, that both Russia and Trump administration officials favor Marine Le Pen for the French presidency and vehemently oppose German chancellor Angela Merkel. Le Pen even visited Trump Tower during the transition. Why? Clearing up the Trump ties to Russia isn’t just a question about what happened in the 2016 election, It’s an ongoing question about the integrity of European democracy.

12. Flynn had a conversation with Russian ambassador Sergey Kislyak in which he allegedly indicated that the incoming Trump administration would lift sanctions or reduce the severity some of the actions of the Obama administration, including new actions announced on December 29, 2016. That wasn’t necessarily out of line for the Trump transition. It violated the ‘one president at a time’ norm, sure. But no one was going to prosecute Flynn under the Logan Act. It was pretty clear all along that the Trump administration wanted to lift at least some sanctions in exchange for a better bilateral relationship with Moscow.

13. Within 24 hours, Trump praised Putin as ‘very smart’ on Twitter, which sure makes it look like he was on the same page with Flynn, who had long ago been appointed as Trump’s national security advisor. It would be more bizarre if Trump and Flynn hadn’t discussed Russia, given its prominent role in the news that week and the new round of Obama sanctions.

14. For whatever reason, Flynn apparently lied or misled vice president Mike Pence about the extent of his conversations with the Russian ambassador, and Pence then used his own credibility to shield questions Flynn. What doesn’t make sense is why Flynn would be so bashful about talking to Russian officials. It’s obvious that the Trump transition team was talking (or at least winking) to many foreign countries — Japan, Israel, Russia. Why hide it? There was a legitimate policy rationale. You might think Trump is being naïve, or you might think it is rude for Trump to step on the toes of the Obama administration. But that the Trump way! Deal with it!

15. Flynn himself has some odd ties to Russia, insofar as he attended a RT commemorative dinner in 2015 and sat at the same table as Putin (and, oddly enough, 2016 Green Party nominee Jill Stein). Flynn also accepted a payment from RT for his attendance at that function. That’s not a crime! The Clinton Foundation shook down dozens of countries for money to fight AIDS and do other good works. None of this is apparently illegal, so long as the payments weren’t from people who were on the US Treasury Department sanctions list. Rex Tillerson, for example, made a lot of deals as ExxonMobil CEO, he made a lot of money from working with the Russian regime and he and his company were vocally critical of US sanctions against Russia and many other places. It wasn’t illegal and it wasn’t a reason (by itself) to derail Tillerson’s nomination as US secretary of state.

16. The FBI was investigating Flynn’s ties to Russia and his inconsistent statements, and the Justice Department knew (and told Trump and top allies) Flynn was subject to blackmail from Russia. Why? We knew all along the Trump team wanted to lift sanctions on Russia. Why not just admit the conversations took place? It wasn’t illegal for Flynn to take money from RT, either, and he had already admitted that. With the FBI and Justice pressuring him, why would Flynn continue to cover up his conversations? That still makes no sense to me.

17. Trump, moreover, knew about the Justice assessment for weeks and did nothing. Pence only found out on February 9. Only after the discrepancies become public knowledge did Trump and the White House seem to think this was any kind of problem.

18. At this point, there are too many flashing red lights to ignore, even for Republicans. Even stalwarts like Missouri senator Roy Blunt, let alone Democratic and hawkish Republican senators like Arizona’s John McCain and South Carolina’s Lindsey Graham, are calling for an independent investigation — and not only about the ties between Flynn and the Kremlin, but all things Trump and the Kremlin. The heart of that inquiry is whether there was any Trump quid pro quo with Russia. Business conflicts? Personal blackmail? Dirty tricks against Clinton?

Trump, above all, needs to have his own name cleared in an independent investigation to regain any credibility as to his administration’s foreign policy. At this point, with Flynn’s resignation, the implications could force Trump into take a more hawkish position on Russia than might otherwise be necessary.

For everyone’s sake, the sooner an investigation can get to the bottom of this, the better.