National security advisor Michael Flynn resigned his position this evening after pre-inaugural conversations with the Russian ambassador which undermined the authority of the President came to light.
During Christmas week, as President Obama was announcing sanctions against the Russians for meddling in the nation's elections, Flynn held numerous conversations with the Russian Ambassador to the US, Sergey Kislyak.
During those calls, transcripts from the FBI show, Flynn discussed the sanctions, implied Trump would take care of them, and asked that the Russians not retaliate. While President Obama's sanctions are still in place, Trump loosened them on February 2.
Flynn initially denied he discussed the sanctions with the ambassador, then changed his story later and said he wasn't sure if he had discussed them or not.
When the details of the calls began to seep out, VP Pence talked to Flynn about the calls and was lied to about their contents. Both he and White House spokesman Sean Spicer publically defended him. According to the New York Times, Flynn also misled other White House officials.
As this story has unfolded over the past several days more details of the conversations have come to light. Today it was disclosed that the US Deparment of Justice was aware of the telephone calls and lies to Pence, and had warned members of the Trump administration that, since the Russians clearly knew of the lies, Flynn was susceptable to blackmail by the Kremlin.
In discussing US sanctions against Russia before Trump had been inaugurated and Flynn sworn in, he was acting as a private citizen and was therefore in violation of the Logan Act.
The NY Times is reporting that Flynn is currently under investigation by the Army for possibly having taken money from the Russian in 2015. According to the paper, he was hired by the Russian Times to attend an anniversary event and sit beside Putin.
Accepting money from the Russians would be a violation of the Emoluments Clause of the Constitution, which prohibits former military officers from receiving money from a foreign government without consent from Congress.
Lt. General Joseph Keith Kellogg, Jr., will be the acting national security adviser until a replacement can be found for Flynn..
Under consideration is General David H. Petraeus. You may recall Petraeus was the former director of the CIA. He was forced to step down when it was revealed he was having an affair with his biographer and had shared classified information with her.