President Trump’s admiration for President Vladimir Putin of Russia has been endlessly dissected, but the American leader’s policy shifts since taking office again could have profound effects.

David Sundberg headed the field office as its agents participated in investigations of Donald Trump, whose administration has asked for resignations from a number of top FBI officials.

A new analysis that began under the Biden administration is released by the C.I.A.’s new director, John Ratcliffe, who wants the agency to get “off the sidelines” in the debate.