Last week, the American public saw for the first time detailed, specific evidence that President Vladimir V. Putin’s military commanders in Russia were engaged in a day-to-day, highly sophisticated effort to manipulate the 2016 election.
But on Monday, standing next to Mr. Putin, President Trump not only avoided all mention of the Justice Department’s indictment of 12 Russian military intelligence officers, but he questioned the very conclusion that Russia was behind the hacking.
Instead, Mr. Trump raised a series of largely irrelevant conspiracy theories — none of which were directly related to the evidence of Russian hacking activity.
He returned to questions of why the F.B.I. never took custody of a Democratic National Committee computer server.
He asked what happened to Imran Awan, a Pakistan-born Capitol Hill aide, who pleaded guilty this month on unrelated fraud charges after becoming a cause célèbre for conservatives who questioned whether he was linked to the committee’s hacking. (A July 3 plea agreement found no evidence that Mr. Awan illegally handled congressional computer systems.)
And Mr. Trump demanded to know why thousands of Hillary Clinton’s emails had disappeared, a question apparently unrelated to Russia’s activities.
It was a smoke-and-mirrors effort, several American intelligence officials said later Monday. While Mr. Trump’s supporters repeatedly return to the question of the Democratic National Committee’s reluctance to turn over its server, which still sits in the committee’s basement, investigators familiar with the intelligence in the case said the hardware itself is of little investigative value.
That is because the emails were always supposed to be stored in the party committee’s server. How they made their way into communications channels and networks used by the G.R.U., Mr. Putin’s aggressive military intelligence unit, is the crux of the investigation. And so is the question of who ordered that they be made public at critical moments in the 2016 campaign.
The Russian president, for his part, was more subtle.
Mr. Putin invited American investigators working for the special counsel, Robert S. Mueller III, to come to Moscow and work with Russian officials in a joint investigation. It was akin to the prime suspect in a homicide offering to join detectives in going house to house in a search for the culprit.
“Putin is just trying to tie this investigation thing up,” said James Lewis, a cybersecurity expert at the Center for Strategic and International Studies.
Mr. Lewis said the Russian president “wants to assert himself as peer.” He noted that Mr. Putin again raised the proposal of a joint cybersecurity working group — an idea that Mr. Trump initially and enthusiastically supported until his staff explained the dangers of potentially undercutting American cyberdefense programs.
“He must just laugh when he gets back to Moscow,” Mr. Lewis said.
Mr. Trump’s own effort at misdirection is not new.
When he first met Mr. Putin a year ago, in Hamburg, Germany, he said the Russian leader had made a persuasive case that Moscow was so skilled at cyberattacks it could not have been involved. Mr. Trump offered a version of the same explanation on Monday, saying Mr. Putin had been enormously persuasive in his denials.
That shocked many of his current and former aides, who say the president has been briefed repeatedly — starting at Trump Tower in Manhattan in January 2017 — on the basis for the conclusion that Mr. Putin himself ordered the attack. The aides said Mr. Trump understands that American, British and Dutch intelligence all intercepted Russian messages and Democratic National Committee documents.
The American president has also been told that the F.B.I. has received a full “forensic copy” of the committee’s server. That is a fairly standard practice and, as the committee noted Monday in a statement, is “the best thing to use in an investigation so that your exploration of the server does not change the evidence.”
And Mr. Trump has been briefed extensively on the specific roles of the newly indicted Russian military commanders in publishing stolen emails and attempts to infiltrate election systems.
His equivocating on Monday left several people who have worked with him to conclude that the president simply will not accept evidence of Russian involvement — fearing it could be used by political enemies to argue he was not legitimately elected.
More than 18 months into his presidency, Mr. Trump has stood alone as the sole senior American official who has questioned the quality of the evidence.
His secretary of state, Mike Pompeo, said he had no doubts about Russia’s involvement when he served as director of the C.I.A. The heads of the National Security Agency and the other leading intelligence agencies have said the same.
Mr. Trump’s director of national intelligence, Dan Coats, went further last week when he argued that the system was “blinking red” about future cyberattacks, maybe intended to affect the next election. On Monday, shortly after his boss questioned whether Mr. Putin or the American intelligence community was right, Mr. Coats responded, “We have been clear in our assessments of Russian meddling in the 2016 election and their ongoing, pervasive efforts to undermine our democracy.”
In a normal political environment, it is easy to imagine a president pursuing the investigation even while making the case that the 2016 outcome was not affected by the Russian activities. Mr. Trump, his closest aides say, has never been able to separate the question of preventing future Russian meddling from his conviction that the entire issue is a political concoction.
The effects of that paralysis are now being seen. At the White House, the job of cybercoordinator — the post responsible for coordinating American defenses — has been eliminated.
The Department of Homeland Security has raised urgent concerns about the vulnerability of American critical infrastructure, including electric utilities, to malware planted by Russian hackers. But Mr. Trump has never led a significant meeting on the subject, aides said. He never created a commission to learn lessons from the 2016 experience.
Now, as was clear in the most awkward moments of the news conference, the issue is more complicated for both Mr. Trump and Mr. Putin.
The intelligence revealed in Friday’s indictment contains such specific conversations between Russian military officers, WikiLeaks and others that it would reasonably leave both presidents concerned about what else from the American intelligence trove may have been turned over to Mr. Mueller. If there were Americans involved, they would have to assume they, too, were caught in the digital dragnet.
Mr. Mueller’s investigation is clearly not yet over, and there are hints in the Friday indictments that he is now trying to establish the links between the Russian hackers and any Americans who may have been working with them. Perhaps that is why Mr. Trump kept returning to his claim that there was no collusion — a question the special counsel has not yet publicly addressed.