4. Why did Flynn direct Russia not to respond to U.S. sanctions?

One of the things to which Flynn pleaded guilty was lying about asking Russia not to respond to the Obama administration's recently announced sanctions in response to Russian interference in the 2016 election:

In another conversation, on Dec. 29, Flynn called the ambassador to ask Russia not to escalate an ongoing feud over sanctions imposed by the Obama administration, court records say. The ambassador later called back and said Russia had chosen not to retaliate, the records say.

There is plenty left out about these conversations. Perhaps the biggest is why Flynn argued that Russia shouldn't escalate the feud over sanctions and why Russia granted his request. Did he simply make a suggestion and not explain why, or did he indicate that the Trump administration might seek to ease those sanctions when it took over less than a month later?

That's been a central question for the better part of a year. And it remains so even after Flynn's plea deal.