Director of National Intelligence James Clapper
Director of National Intelligence James Clapper

In a hearing on Capitol Hill Thursday, U.S. intelligence leaders doubled down on their collective assertion that Russia intentionally interfered with the 2016 presidential election, even as President-elect Donald Trump continues to publicly cast doubt on these findings.

In testimony before the U.S. Senate Committee on Armed Services, outgoing Director of National Intelligence James Clapper said that intel officials “stand even more resolutely” in their convictions today than they were on Oct. 7 when Clapper's office and the Department of Homeland Security issued a joint statement accusing Russia of hacking the emails of key U.S. political organizations.

Clapper noted that the hacking was only one part of Russia's multifaceted campaign, which “also entailed classical propaganda, disinformation and fake news.” The director was supported by additional testimony from Admiral Michael Rogers, director of the National Security Agency and commander of the U.S. Cyber Command, and Marcel Lettre, the under secretary of defense for intelligence.

Clapper and Rogers in particular made statements to discredit WikiLeaks founder Julian Assange, who claims that Russia was not the source that provided his website with damaging emails stolen from the Democratic National Committee and Hillary Clinton campaign chairman John Podesta. Trump and his surrogates have cited Assange's assertions as a possible alternative theory to Russia meddling in U.S. affairs, prompting alarm from some key legislators on both sides of the aisle, including Sen. John McCain (R-Ariz.), the chairman of the Armed Services Committee.

“I believe that [Assange] is the one who's responsible for publishing names of individuals that work for us that put their lives in direct danger, is that correct?” McCain asked Clapper.

“Yes, he has,” Clapper responded.

“And do you think that there's any credibility we should attach to this individual, given his record…?”

“Not in my view,” answered Clapper, later adding, “I don't think those of us in the intelligence community have a whole lot of respect for him.”

“I would echo those comments,” said Admiral Rogers.

Despite Assange's claims and Trump's doubts, 17 U.S. intelligence agencies agree that Russia engaged in a cyber campaign – endorsed by President Vladimir Putin himself – designed to destabilize the U.S. democratic process and cast doubt on the veracity of American elections. The CIA and FBI also have reported that Russia wanted to swing the election in favor of Trump.

The CIA, FBI and NSA plan to release a joint report next week that will further elaborate on these accusations. Though he was unable to provide many details of this report in his testimony, Clapper did state that Russia had “more than one motive” for its involvement. Last week, the DHS and FBI released a 13-page joint analysis report (JAR) detailing the campaign, dubbed Grizzly Steppe.

Officials are confident that hackers did not physically change any vote tallies by sabotaging electoral systems, but Russia's alleged actions nevertheless could have influenced American citizens on how to vote.

“There's no escaping the fact that this committee meets today for the first time in this new Congress in the aftermath of an unprecedented attack on our democracy,” said McCain. “There is no national security interest more vital to the United States of American than the ability to free and fair hold elections without foreign interference.”

As for Trump's public dismissal of current U.S. intelligence reports, Clapper said that a little “healthy skepticism” is encouraged, but added, “I think there's a difference between skepticism and disparagement,” said Clapper.

While the testimony had a distinctly Russian flavor to it, the hearing actually sought to examine all current foreign cyber threats, including campaigns launched by China, Iran, North Korea and terrorist groups.

Admiral Rogers warned that all of these groups are growing increasingly proficient at launching attacks and that intelligence agencies must become more agile to quickly respond to these threats.

U.S. intelligence agencies typically defend against and respond to cyber incidents on a case-by-case basis, said Lettre, a policy that did not sit well with some committee members, including McCain. Some Republicans also chastised President Barack Obama not not responding decisively enough to Russia's actions, even after the current administration imposed new sanctions and expelled 35 Russian diplomats last week.

"What seems clear is that our adversaries have reached a common conclusion that the reward for attacking America in cyberspace outweighs the risk," said McCain. "For years, cyberattacks on our nation have been met with indecision and inaction. "Our nation has no policy and thus no strategy for cyber deterrents. "This appearance of weakness has been provocative to our adversaries, who have attacked us again and again with growing severity."

Lettre said the U.S. must impose a cost on countries that perpetrate cyber attacks, citing the recent sanctions against Russia as a prime example. "Sanctions are a very useful tool... and I think in the case of the current situation that we find ourselves in, it would be prudent to continue to look at other options to impose more sanctions on Russian actors as the facts continue to develop."

In their respective testimonies, Clapper, Lettre and Rogers named several key objectives for intel agencies to pursue in the coming years. Among them: refining U.S. cyber policies, developing effective deterrents to prevent foreign attacks, determining appropriate responses (both cyber and non-cyber) for various attack scenarios, continuing to innovate, and splitting U.S. Cyber Command from the NSA.