Who knew what and when and were they going to act?

President Donald Trump, Vice President Mike Pence (middle), and National Security Adviser Michael Flynn (right). Flynn resigned as President Donald Trump's national security adviser Monday. Photo / AP

December 30
• Flynn, a former lieutenant general who had been selected as Trump's national security adviser, speaks to Russia's ambassador to the United States, Sergey Kislyak. Despite Flynn's later denial and the White House's later comments, he and Kislyak discuss sanctions and the possibility of relieving them once Trump is President - even as the Obama Administration was announcing new sanctions for Russia's alleged meddling in the 2016 election.

January 13
• For the first time, Flynn's talks with the Russian ambassador are reported by the Washington Post. Few details are known, but columnist David Ignatius notes that if the two discussed the sanctions, this could violate an obscure law known as the Logan Act, which prohibits unauthorised citizens from dealing in disputes with foreign governments.

January 14
• Trump's press secretary Sean Spicer says Flynn told him that he had exchanged text messages with Kislyak before they spoke on December 30 to discuss logistics for a call between Russian President Vladimir Putin and Trump after Trump was sworn in as president.

January 15
• Flynn assures Mike Pence, who was then the Vice-President-elect, that the two of them didn't discuss sanctions, according to Pence.

January 16
• Pence says on the TV shows that Flynn and Kislyak didn't discuss sanctions.

January 21
• Trump becomes President. Within days Flynn is interviewed by the FBI over his communication with Kislyak.

January 27
• The Justice Department, then headed by acting Attorney General Sally Yates (whom Trump would later dismiss for not defending his travel ban), informs White House counsel Don McGahn of Flynn's misleading statements. It also warns that they were so egregious that he could open himself up to Russian blackmail. Spicer later says that "the President was immediately informed of the situation", but that the White House didn't believe Flynn had violated the law. None of this was disclosed publicly at the time.

February 9
• Flynn denies having discussed sanctions with Kislyak.

February 10
• The Post reports that Flynn did, in fact, discuss sanctions with the Russian ambassador. A spokesperson says Flynn "couldn't be certain that the topic never came up".

February 11
• Trump says he is unaware of the Post report but will "look into" it.

Tuesday:
• Senior adviser Kellyanne Conway says the White House has "full confidence" in Flynn.

• Spicer says "the President is evaluating the situation", and is "speaking to the Vice-President relative to the conversation the Vice-President had with General Flynn".

• The Post reports that the Justice Department had told the White House last month "that Flynn had so mischaracterised his communications with the Russian diplomat that he might be vulnerable to blackmail".

• Flynn resigns.

Yesterday
• Conway says Flynn resigned voluntarily.

• Spicer, again contradicting Conway, says Trump requested the resignation: "Whether or not he actually misled the Vice-President was the issue, and that was ultimately what led to the President asking for and accepting the resignation of General Flynn."

A few questions on this
• Was the Administration planning to take any action based on the Justice Department's late-January news of Flynn having misled them?

• Trump said he hadn't heard about the Post story on Flynn having misled his Administration as recently as February 11. Did the White House counsel really not inform the President about what the Justice Department had said? Or was it perhaps disregarded once Yates, an Obama appointee, was dismissed?

• Do White House officials truly accept Flynn's contention that he simply forgot about discussing sanctions? Conway's comments suggest they do. But Russian sanctions were one of the biggest stories in US foreign policy at the time.

• Even if Flynn did truly forget, would it be okay that he discussed something he wasn't supposed to during the phone call?