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

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.