Two days into the first week of Donald J. Trump’s presidency, the Senate launched a probe into alleged hacking of his victory by Russia.

The move could deepen the rift between the new president and the intelligence community — which has said that Russia intervened in the U.S. election with the goal of helping to elect Trump. It could also eventually drive a wedge between Trump and the Republican Congress, depending on the information that is uncovered and how aggressively lawmakers move to follow it.

The Senate Intelligence Committee, which is in charge of the chamber’s investigation, kicked off the probe Tuesday with a meeting to establish the scope of their inquiries. Lawmakers have pledged to look “everywhere the intelligence tells us to go” on Russia’s activities in the 2016 elections, according to chairman Richard Burr, R-N.C. — even if that includes uncovering direct links between the Trump campaign and the Kremlin.

In the next week or two, Senate Armed Services Committee Chairman John McCain, R-Ariz., said his committee will launch its official investigation into how best to deter and counteract cyber-threats posed by countries such as Russia. He plans to do so with at least one full committee hearing, calling on officials like Adm. Mike Rogers – the director of the National Security Agency and the commander of U.S. Cyber Command – to testify.

But Republican leaders are not promising a quick turnaround.

Burr surmised that it would take months to “aggressively” comb through all the intelligence pertaining to the suspected hacking, given the scale and extent of them aren’t yet clear. And elsewhere in Congress, Republican leaders are clearly waiting on the Intelligence panel to take the lead.

“It’s not much of a foreign policy role, once you had the briefing we had the other day,” said Senate Foreign Relations Committee Chairman Bob Corker, R-Tenn. He was referring to a briefing the nation’s spy chiefs gave to the full Senate in the days preceding Trump’s inauguration.

“The intelligence community is really robust in what they’re doing and if you’re really trying to look at what happened during the election, the runup to the election, that’s really the committee that should be looking at that anyway,” added Corker.

“At present, we can’t even get witnesses, or anybody in intelligence” to testify because “they’re off-limits to all of us.”

Homeland Security and Government Affairs Committee Chairman Ron Johnson, R-Wis., said earlier this month he had no plans to investigate the Russian hacking allegations in his panel. The Senate Banking Committee has also not outlined plans for any major investigations, though they have jurisdiction over any sanctions to step up punitive actions against Russia.

That leaves the Armed Services Committee to tackle how the U.S. should marshal its defense and national security resources to deter – or in the worst case respond to – another cyberattack.

Following that, at an undetermined point in the future, the plan is to hand off the day-to-day of that investigation to the head of a new cyber-security subcommittee, Sen. Mike Rounds, R-S.D.

But Rounds will not have a free hand. Though the full membership of the cyber subcommittee has not yet been set, McCain has decided to award one of the rank-and-file seats to himself. Rounds has already promised that he is “not going to overstep my bounds” when it comes to the chairman.

Rounds, a first-term senator and former governor of South Dakota, was the last-minute pick to replace close McCain confidante Sen. Lindsey Graham, R-S.C., who opted not to seek the waiver necessary to take on the cyber subcommittee as his third subcommittee chairmanship.

Graham has secured such a waiver before, but both he and McCain cast the move as practical, denying that Senate GOP leaders might not agree to let Graham, the conference’s loudest Trump critic, spearhead what is likely to be the Senate’s highest-profile investigation into hacks that could implicate the Republican president.

In an interview, Rounds said he has confidence in the new administration because of Trump’s national security picks — particularly Gen. James Mattis as Pentagon chief. Rounds said he is “not looking for a fight” with officials, but added that he is prepared “to go wherever the information takes us,” promising “we’re going to get results.”

Rounds has lobbied for cyber security responses in relatively quiet anonymity, but his signature mark in the arena is the current law, passed as part of a massive defense bill last year, insisting the Pentagon define when a cyber breach or attack constitutes an act of war.

His goal now is to craft policy describing what to do in the event of a cyber attack. He would not outline his ideal terms, pledge to fully publicize the results or endorse new sanctions on Russia. He noted, that “if Congress places sanctions on [Russia], the administration can’t simply decide not to enforce them.”

But Rounds said that would-be hackers and adversaries should understand there will be “serious repercussions” for anyone trying in the future to interfere with an election through cyberspace.

“We should not take anything off the table,” he said, likening cyber attacks to other acts of war. “What we would do in regard to a [physical] attack, we should also be able to use for a cyber attack.”

(c) 2017, The Washington Post · Karoun Demirjian