After the election, they continued to spread confusion and chaos, staging rallies both for and against Mr. Trump, in one case on the same day and in the same city.

All along, they took steps to cover their tracks by stealing the identities of real Americans, opening accounts on American-based servers and lying about what their money was being used for. Last September, after Facebook turned over information about Russian ad purchases to the special counsel, a specialist named Irina Kaverzina emailed a family member: “We had a slight crisis here at work: the FBI busted our activity (not a joke). So, I got preoccupied with covering tracks together with the colleagues.” Ms. Kaverzina continued, “I created all these pictures and posts, and the Americans believed that it was written by their people.”

Fake news, indeed.

Mr. Trump’s defenders, desperate to exculpate him, seized on a single word — “unwitting” — that the indictment used to describe certain “members, volunteers and supporters of the Trump campaign involved in local community outreach” who had interacted with the Russians.

In other words, as the White House subtly put it in a statement on Friday, “NO COLLUSION.” The president repeated the claim himself in a tweet, grudgingly acknowledging Russia’s “anti-US campaign,” but emphasizing that it had started “long before I announced that I would run for President. The results of the election were not impacted. The Trump campaign did nothing wrong — no collusion!”

It’s true that, as Deputy Attorney General Rod Rosenstein said in an announcement, these particular indictments do not allege that any American knew about the influence campaign, nor that the campaign had changed the outcome of the election. But that’s quite different from saying that there was no collusion or impact on the election. As Mr. Rosenstein also said, the special counsel’s investigation is continuing, and there are many strands the public still knows little or nothing about.

Remember, Mr. Mueller has already secured two guilty pleas, one from Mr. Trump’s former national security adviser and another from a former campaign adviser, for lying to federal authorities about their connections to Russian government officials. He has also charged Mr. Trump’s former campaign chairman, Paul Manafort, and his top aide, Rick Gates, with crimes including money laundering. Mr. Gates appears to be nearing a plea deal himself.

Then there were Russian cyberattacks on the elections systems of at least 39 states. And the hacking of emails sent among members of the Democratic National Committee and the Clinton campaign — which Mr. Trump openly encouraged.

This is all going to happen again. Intelligence and law enforcement authorities have made that clear. The question is whether Mr. Trump will at last accept the fact of Russian interference and take aggressive measures to protect American democracy. For starters, he could impose the sanctions on Russia that Congress overwhelmingly passed, and that he signed into law, last summer. Of course, this would require him to overcome his mysterious resistance to acting against Russia and to focus on protecting his own country.