William Brangham:

As the presidential campaign continues in the fall of 2016, American intelligence officials brief members of Congress that the Russian government is looking to interfere in the election.

In September, at the G20 meeting in China, President Obama warns Russian President Vladimir Putin to stop his nation's interference. Two months later, Donald Trump wins the presidency, but, before his inauguration, the Obama administration publicly points the finger at Russia for the Clinton e-mail hack, and, in retaliation, levies sanctions on Russia and expels 35 Russian nationals from the U.S.

The next month, a declassified intelligence report from the FBI, the CIA, and the NSA states with high confidence that Vladimir Putin personally ordered a cyber and social media campaign to disrupt the recent U.S. presidential election.

And it states that Putin had a clear preference for Donald Trump. According to the report, Putin — quote — "aspired to help president-elect Trump's election chances when possible by discrediting Secretary Clinton and publicly contrasting her unfavorably to him."

In February of 2018, Robert Mueller's first indictment against the Russians drops.