In other words, Mueller charged Flynn with a crime that everyone knew he committed, and has known he committed for months. His quick plea, and the skeletal charging document, point to any number of other potential crimes, whether publicly discussed or not.
Certainly, there’s a range of questionable conduct for Mueller to investigate. Like Manafort, Flynn retroactively filed under the Foreign Agent Registration Act for lobbying, in Flynn’s case for work on behalf of Turkey that occurred during the campaign and ended (per Flynn) only with Flynn’s November 2016 appointment as national-security adviser. The plea deal stipulates that Flynn made “materially false statements and representations” in his March 2017 FARA filings that disclosed this work, but those were not among the statements for which he was charged. That’s at least one clear instance in which Mueller is aware of criminal misconduct which he has chosen not to prosecute at this stage of his investigation.
That’s not all. According to reports and an account from former CIA Director James Woolsey, Flynn discussed a plot to kidnap Fethullah Gulen, the Turkish cleric living in self-imposed exile in Pennsylvania, whom the Turkish government accuses of fomenting a failed 2016 coup, and bundle him off to Turkey. Flynn also reportedly pushed a business plan on which he’d been a paid consultant after he entered the White House, a potential misuse of his office.
Flynn could also be in trouble for things he did before he was appointed national-security adviser. After leaving the military, Flynn was paid for trips overseas, including one to Russia for a fete celebrating RT, the Kremlin-backed news and propaganda outlet; at dinner, Flynn was seated with President Vladimir Putin. As former top brass, Flynn should have sought Pentagon permission before taking those trips; he also should have disclosed them when applying to renew his security clearance in 2016. Members of Congress allege that Flynn did neither.
These are only the incidents which have been publicly reported. Mueller may or may not know of other possible misdeeds.
The obvious question any time someone is caught lying to the FBI is, How could they have been so stupid? This is especially true in the case of Flynn, the former head of the Defense Intelligence Agency. As a decorated and accomplished intelligence officer, he should have known that conversations with the Russian ambassador might be surveilled, producing irrefutable evidence that he was lying. His decision to lie about such a black-and-white matter raises questions about whether he might have hoped to cover something up.
The plea once again raises questions about the president’s judgment, both in hiring Flynn and afterwards. Flynn’s firing from the DIA by President Obama for mismanagement ought to have been a red flag. The campaign did not effectively vet Flynn, failing to turn up the missing security-clearance disclosures. The New York Times reports that Flynn told the Trump transition team in January that he was under investigation for undisclosed lobbying on behalf of Turkey. Top White House officials deny they were informed.