Michael Flynn’s plea deal with prosecutors in special counsel Robert Mueller’s Russia probe is a watershed moment for President Donald Trump — one that leaves him with two choices, each with clear risks.

Flynn, who was Trump’s national security adviser for 24 days and was also a top campaign adviser, has admitted to lying to the FBI about two of his conversations with former Russian Ambassador Sergey Kislyak in December 2016.

But here’s the kicker: Flynn told investigators that “a very senior member” of Trump’s presidential transition team told him to make contact with Russian government officials — in other words, he’s now claiming he was just following orders when he went to talk to the Russians.

Which means that Flynn’s plea deal and cooperation with the Mueller investigation could potentially implicate senior members of Trump’s inner circle, or even the president himself, in at the very least some questionable behavior. Indeed, reports have suggested that Trump’s senior adviser and son-in-law Jared Kushner may have been one of the senior officials of the transition team who directed Flynn to speak to the Russians.

So at this point, Trump has two options for how to respond to all of this: try to make it all go away, or just try to minimize the potential damage. In other words: betray Flynn or fire Mueller.

Betraying Flynn seems like the better option, even though it will lead to weeks of reports about the hypocrisy and outright lies of the Trump administration. But that seems far more preferable — and less risky — to firing Mueller, which could spark a massive political and constitutional crisis.

Option 1: minimize Flynn’s importance to Trumpworld

Trump could try to downplay the significance of Flynn’s plea deal, saying that it still doesn’t implicate him or other members of his campaign. He could also try to downplay Flynn’s role in his campaign, making it seem like Flynn wasn’t an important figure during the election and that any interactions he had with Russians wouldn’t have come from the top.

Early indications suggest that this may be the strategy the president’s lawyers are pursuing. Top White House lawyer Ty Cobb said in a statement shortly after the announcement of the plea deal that “[n]othing about the guilty plea or the charge implicates anyone other than Mr. Flynn.”

That may be true for now. But the fact that Flynn is cooperating with the investigation means he could potentially give Mueller’s team information that does implicate other people in the Trump orbit.

And trying to downplay Flynn’s involvement in the campaign would be a hard sell. Flynn, a former three-star general and Obama administration intelligence official, joined the campaign in February 2016 and immediately became a prominent campaign surrogate, offering Trump some credibility on foreign policy and national security affairs — two areas where Trump had no prior experience.

He led chants of “Lock her up!” during the Republican National Convention on July 18, 2016, referring to Hillary Clinton and the probe into her use of a private email server when she was secretary of state.

And on November 17, 2016, just nine days after the election, Trump named Flynn as his national security adviser. That made Flynn one of the most powerful people in Washington, with responsibilities for overseeing and coordinating America’s wars, intelligence gathering, and diplomacy. (Flynn resigned in February after lying to Vice President Mike Pence about the content of his conversations with Kislyak in December — the same conversations Flynn now admits to having lied to the FBI about in January.)

Even once Flynn was gone, Trump still went to bat for him — going as far as asking then-FBI Director James Comey to drop the investigation into Flynn entirely. An assertion that Flynn wasn’t an important figure in the Trump inner circle would beggar belief.

To be fair, Trump has no problem lying in general — especially to the press — and he’s no stranger to negative press coverage and shouts of hypocrisy. So throwing Flynn under the bus may actually be the safer option for him. But there’s a bleaker choice for Trump — firing Mueller — which could lead to a lot more trouble.

Option 2: fire Mueller and spark a political and constitutional crisis

The second option would be to fire Mueller in an attempt to end the probe altogether and prevent Mueller from using Flynn’s cooperation to build a case against the president, his family, or other top aides.

Trump has mused about firing Mueller before, but held off, in part because senior lawmakers from both parties have warned him of serious and immediate consequences if he chose to do so. To many establishment Republicans, the prospect that Trump would fire Mueller is unimaginable. “I cannot possibly imagine the president terminating Bob Mueller,” Sen. Bob Corker (R-TN) said in June. “It just cannot happen.”

But now that Flynn is cooperating with the special counsel, Trump might decide it’s worth the risk to let Mueller go — which could lead to outcries on Capitol Hill, even from Republicans.

There’s another potential problem for Trump, though: Getting rid of Mueller might not actually be as easy as it sounds.

That’s because Deputy Attorney General Rod Rosenstein told Congress back in June that he interpreted the special counsel regulation to mean that he (Rosenstein) is the only person in government with the authority to fire Mueller — not the president. And he said that he would only fire Mueller for “good cause,” and would refuse to carry out an order from the president to fire Mueller if good cause were not established.

It’s doubtful that Rosenstein would consider Trump not wanting himself, his family, or his close aides to potentially be indicted on criminal charges to be “good cause,” and would thus refuse to fire Mueller. Which means Trump would have to fire Rosenstein — and perhaps several more Justice Department officials — until he found one willing to carry out his order.

That could get very, very messy — and potentially provoke a constitutional crisis. Here’s why: Throughout the entire process, Trump would purposely be trying to kill an investigation that could charge him, his family members, or his close associates with crimes. That would mean he was putting his personal interests above the law — and no president is above the law. It would be a blatant attempt at a cover-up.

Senators on both sides of the aisle, including Sens. Thom Tillis (R-NC) and Chris Coons (D-DE), have proposed a bill to protect Mueller and avoid such a scenario.

Explaining his proposed bill, Tillis told CNN in August, "The President would maintain the power to remove the special counsel, but we would just want to make sure that it had merit and have that back-end judicial process.”

“And if there is a termination, we just want to make sure, through judicial review, that it was warranted,” he added.

Congress has yet to pass that bill, though, which means that Trump could still fire Mueller and potentially provoke a showdown with the Justice Department. That’s why Coons seems adamant that he will continue to push his bill.

“It’s now more important than ever that Special Counsel Mueller is able to continue his investigation without interference, and I am continuing to work on bipartisan legislation to protect the special counsel from being fired without cause,” Coons said in a statement on Friday.