There's debate in the Obama administration about how to respond to the hacks targeting Democratic Party organizations and increasing evidence that Russian hackers also were behind attacks on election registration websites.
FBI and Justice Department officials believe there's strong evidence to warrant publicly naming Russia as responsible for the political organization attacks, law enforcement and intelligence officials briefed on the investigation say.
But there is opposition from US intelligence agencies and the Office of the Director of National Intelligence, who have cautioned about moving to "name and shame" Russia, in part because of concerns about Russian retaliation and the possible exposure of US intelligence operations, the routine spy work that the US carries out against Russia and other countries.
White House officials, meanwhile, are cautious for other reasons, administration officials say: the political overtones of making such an attribution against Russia weeks before the US presidential election. Some White House officials also believe the FBI and intelligence agencies have more work to do to show definitive links between Russian intelligence hackers, whom US investigators believe stole documents from the Democratic National Committee, and WikiLeaks, the organization that published the material
the weekend before the Democratic Party's convention.
An administration official said there's no effort to slow down attribution of the hacks.
"As senior law enforcement officials have said, there is an active, ongoing investigation into recent cyberintrusions against the DNC and related entities," the official said. "The law enforcement and intelligence communities will reach their own conclusions in due course. Policy decisions regarding public attribution for these intrusions are contingent on the results of that investigation, which we are careful not to get ahead of."
Intelligence and law enforcement officials don't believe the Russian goal is necessarily to get a particular candidate elected. Instead, the goal appears to be to sow dissension and raise doubts about the US political system, according to US intelligence and law enforcement officials. It's similar to Russian activity in recent years in Europe, the officials said.
Putin "is taking advantage of the political environment in the US right now," one US official said.
The US dilemma is particularly notable on Capitol Hill.
This week, congressional leaders and staff returned from vacation and received briefings on the sprawling US hacking investigation. They were told by US intelligence and law enforcement officials that there is now near-certainty that Russian intelligence is behind cyberhacking attacks against targets ranging from the DNC and other political organizations tied to Democrats to Washington think-tanks and even reporters at The New York Times, according to US officials familiar with the briefings.
There's also increasing confidence that recent attacks
against election registration websites in Illinois and Arizona link back to Russian government hackers, though those ties are still being examined, the officials said.
The briefing was persuasive for some Republican lawmakers and staff who have been skeptical of claims by Democrats and Hillary Clinton's campaign of Russian involvement, according to congressional aides. That could pose new discomfort for members of Congress who have endorsed Donald Trump and who focus on national security.
Trump and his campaign have cast doubt about Russian involvement.
"I think it's probably unlikely. Maybe the Democrats are putting that out -- who knows," Trump said in an interview with Larry King that aired on Russia Today
. "If they are doing something, I hope that somebody's going to be able to find out so they can end it. Because that would not be appropriate at all."
The prospect of Russian hacking activity affecting confidence in the US election is foremost in the minds of US government officials.
US officials don't view the hacks of election-registration websites to be a threat to the vote count
. Voting machines and tabulations systems aren't connected to the Internet, which would be the way hackers could tamper with results.
"It would be very difficult to -- through any sort of cyberintrusion -- to alter the ballot count, simply because it is so decentralized and so vast," Homeland Security Secretary Jeh Johnson said Thursday. "You've got state governments, county governments, local governments involved in the election process. It would be very difficult to alter the count."
There are concerns, however, about hackers tampering with registration data and causing voters to show up at their polling places on election day to find they aren't on the voting rolls. While those types of problems are common and happen during every election, the heightened concern about Russian hacks could amplify such issues this year. And that, officials fear, could affect public confidence in the election outcome.
"There are troubling signs that hostile foreign cyberactors are working to undermine our political process," Rep. Michael McCaul, chairman of the House Homeland Security Committee, said in a statement. "This is a direct provocation that goes to the heart of American democracy. Every American should be able to walk away from the ballot box and know that their voice has been heard. We cannot allow such action to go unanswered, which is why President Obama should send a clear signal to intruders: attempts to influence US elections or destabilize the integrity of our electoral process will be met with severe consequences."