A Conspiracy or Not? Here’s What We Know About the Mueller Case

As Mr. Trump’s director of the Central Intelligence Agency, Mike Pompeo branded WikiLeaks a stateless hostile intelligence unit eager to do the bidding of Russia and other American adversaries.

But the special counsel has not, so far, said that WikiLeaks was acting as an agent of the Russian government during the 2016 presidential race, much less claimed that the Trump campaign knew it was dealing with a Russian agent.

It is not even entirely clear that WikiLeaks knew the source of its information was Russia. Russian operatives transferred the pilfered documents to the organization using a fake online persona, Guccifer 2.0.

Mr. Stone himself defended WikiLeaks last year in a cable news interview. Asked if working with the organization would be treasonous, he replied: “No, actually, I don’t think so because for it to be a treasonous act, Assange would have to be probably a Russian asset and WikiLeaks would have to be a Russian front, and I do not believe that is the case.”

Whether prosecutors think so is unclear. Last year, the Justice Department inadvertently revealed that it had secretly charged Mr. Assange, but it remains unclear for what crimes. Mr. Assange has been holed up in the Ecuadorean Embassy in London for years for fear of criminal prosecution.

The president publicly encouraged Russian operatives to infiltrate Mrs. Clinton’s emails during the 2016 campaign, saying they would “probably be rewarded mightily by our press” if they uncovered the messages. That same day, Russian hackers tried to break into servers that housed the emails for Mrs. Clinton’s personal office, according to court documents Mr. Mueller filed last year.

But that alone is far from enough to land Mr. Trump in legal hot water.

Legal experts said that prosecutors would need evidence that the Russians and Mr. Trump were working together — not merely that he encouraged computer espionage.

“It’s can’t just be cause and effect, there has to be some type of agreement — whether explicit or implicit — that shows they were working together and prosecutors would have to have the evidence to prove that beyond a reasonable doubt,” said Joyce Vance, a professor of law at the University of Alabama and former United States attorney.