How did American intelligence officials come to brief President Obama, President-elect Donald J. Trump and lawmakers about supposed Russian plans to try to blackmail Trump? There are far more questions than answers.
But here is a look at the story so far.
What we know
• Last year, a Washington political research firm, paid by Trump’s Republican rivals, hired a retired British intelligence officer to investigate the candidate’s ties to Russia.
• After it became clear that Trump would be the Republican.....