By Seth Wenig/AP/REX/Shutterstock.

As Robert Mueller’s probe into potential collusion between Donald Trump’s campaign and Russia and possible obstruction of justice pressed on, Trump’s lawyers seemed to coalesce around one condition: the special counsel must not interview the president. For weeks, reports focused on the back-and-forth between the president’s legal team and Mueller’s office as they negotiated a potential interview, the collective imagination ignited by the thought of the special counsel going head-to-head with the notoriously untruthful president. On the air, Rudy Giuliani lamented that Mueller was attempting to lay a “perjury trap.” And yet, after all the seemingly tense exchanges, and even the unspoken threat of a subpoena, Mueller ended his probe apparently without interviewing its prime witness.

Why exactly that is, and whether Mueller’s conclusion would have been different with input from Trump, is now a matter left to speculation, in part because the full report has not been made public by Attorney General William Barr, who summarized its findings in a brief, controversial letter last weekend. But a postmortem by The Washington Post published Thursday digs into the strategy on both sides of the battle, pulling back the curtain on how Trump’s team helped him avoid an interview while flicking at some of the reasons Mueller may have backed down.

As Giuliani and others in Trump’s corner told the Post, their strategy was something of a one-two punch: public admonition of Mueller’s efforts, while privately satisfying investigators’ document requests in an effort to build an argument that the cooperation rendered a presidential interview unnecessary. “No matter what question they would say they wanted to ask, I felt confident we could turn it over and say, ‘You already have the answer to it,’” Giuliani told the paper.

Mueller’s team, of course, has remained characteristically tight-lipped about its decision-making, though Robert Ray, a former independent counsel, noted that subpoenaing Trump would have been precedent-setting, and could have dragged the probe into a long, bitter court battle. “That’s a major fight, and you have to decide whether, in the country’s best interests, it’s worth it,” he said. (White House officials declined the Post’s request for comment.)

Still, such a fight may have been vital, particularly in the special counsel’s inquiry into obstruction of justice, which according to Barr was left an open question. Trump relentlessly railed against the investigation in public comments, and at times seemed to take direct action to undermine it, including firing former F.B.I. director James Comey, which he told Lester Holt in a televised interview was made with “this Russia thing” in mind. The president also reportedly had a hand in drafting a misleading statement for his son Donald Trump Jr. to explain away a shady meeting he took in 2016 in an apparent effort to obtain Russia-proffered dirt on Hillary Clinton.

In his letter, Barr said that he and deputy attorney general Rod Rosenstein had decided that the evidence Mueller compiled was “not sufficient to establish that the President committed an obstruction-of-justice offense” because it did not prove the president acted with “corrupt intent.” An interview with Trump could have gone a long way in establishing said intent—something his legal team presumably knew as it attempted to head off a meeting. “The president would not have helped his case had he gone in,” Mark Corallo, a former spokesperson for Trump’s legal team, told the Post. Former White House lawyer John Dowd reportedly thought so, too. Two people familiar with the matter told the Post that the two sides got as far as scheduling an interview for January 2018. But Dowd stepped in to cancel the session:

He had argued against it because he feared Trump could misspeak or even lie. And a practice session with the president further convinced Dowd that the president could be a problematic interviewee, these people said.

Whatever the reason, Mueller appeared to back down in what the Trump team clearly sees as a win. And after Barr’s Trump-friendly assessment of the report, the president and his allies have embarked on a victory lap. “After three years of lies and spin and slander, the Russia hoax is finally dead,” Trump said at a rally Thursday night, his first since the probe came to its “beautiful conclusion.” “The special counsel completed its report and found no collusion and no obstruction. I could have told you that two and a half years ago. Total exoneration. Complete vindication.”