Ms. Butina’s efforts to deal in Russian jet fuel, detailed in hundreds of pages of previously unreported emails, were notable not just for their whiff of foreign intrigue but for who they involved: David Keene, a former president of the National Rifle Association and a prominent leader of the conservative movement, who has advised Republican candidates from Ronald Reagan to Mitt Romney. They also involved Mr. Keene’s wife, Donna, a well-connected Washington lobbyist, and Ms. Butina’s boyfriend, Paul Erickson, who ran Patrick J. Buchanan’s 1992 presidential campaign and who moved in rarefied conservative circles despite allegations of fraud in three states.

Sitting in a hotel bar, Alexander Nix, who runs the political data firm Cambridge Analytica, had a few ideas for a prospective client looking  for help in a foreign election. The firm could send an attractive woman to seduce a rival candidate and secretly videotape the encounter, Mr. Nix said, or send someone posing as a wealthy land developer to pass a bribe.“We have a long history of working behind the scenes,” Mr. Nix said.

Cambridge Analytica harvested personal information from a huge swath of the electorate to develop techniques that were later used in the Trump campaign. Details of Cambridge’s acquisition and use of Facebook data have surfaced in several accounts since the business began working on the 2016 campaign, setting off a furious debate about the merits of the firm’s so-called psychographic modeling techniques. But the full scale of the data leak involving Americans has not been previously disclosed — and Facebook, until now, has not acknowledged it.

All C.I.A. directors must balance the political demands of the president they serve with the agency’s avowedly apolitical idea of itself. Yet rarely has a director had to straddle so wide a breach as has Mr. Pompeo, perhaps the most openly political spy chief in a generation — and one of President Trump’s favorite cabinet members. Unlike past directors, who typically sought to avoid policy discussions, Mr.  Pompeo readily joins in when the president asks for his opinion, even on matters far afield of national security, such as health care. And he brings to the table the views of a former congressman first elected in the Tea Party wave of 2010 who staked out ground on the far right of the Republican Party.

American spies collected information last summer revealing that senior Russian intelligence and political officials were discussing how to exert influence over Donald J. Trump through his advisers, according to three current and former American officials familiar with the intelligence.

Michael T. Flynn, the national security adviser who was forced out of the job in February, failed to list payments from Russia-linked entities on the first of two financial disclosure forms released Saturday by the Trump administration. The first form, which he signed in February, does not directly mention a paid speech he gave in Moscow, as well as other payments from companies linked to Russia. The second, an amended version, lists the names of the companies that made the payments under a section for any nongovernment compensation that exceeds $5,000 “in a year.” That list appears to include all of the work that Mr. Flynn, a retired three-star Army general, has done since leaving the military in 2014, without providing compensation figures for any of it.

The chiefs of America’s intelligence agencies last week presented President Obama and President-elect Donald J. Trump with a summary of unsubstantiated reports that Russia had collected compromising and salacious personal information about Mr. Trump, two officials with knowledge of the briefing said. The summary is based on memos generated by political operatives seeking to derail Mr. Trump’s candidacy. Details of the reports began circulating in the fall and were widely known among journalists and politicians in Washington.

President-elect Donald J. Trump on Thursday named David M. Friedman, a bankruptcy lawyer aligned with the Israeli far right, as his nominee for ambassador to Israel, elevating a campaign adviser who has questioned the need for a two-state  solution and has likened left-leaning Jews in America to the Jews who  aided the Nazis in the Holocaust.