WASHINGTON – On page after page, special counsel Robert Mueller detailed an elaborate, sophisticated Russian operation to sow division in the U.S. and interfere in the 2016 presidential election by using cyberattacks and social media as weapons.

The Russians’ methods may have been new. But their goal was not.

Since the Cold War, Russia has worked to create a fractious West that no longer poses an existential threat.

Their success in 2016, experts warn, virtually guarantees they’ll try again.

“We’ve been focused on what has happened. We’ve focused almost nothing on how to prevent it in the future,” said Michael McFaul, who served as the U.S. ambassador to Russia under President Barack Obama.

“I think those are things we need to look at hard,” McFaul said. “Because time is short.”

‘A significant escalation’

Mueller’s 448-page report, released to Congress and the public on Thursday after a nearly two-year investigation, provided the most comprehensive description to date of Russia’s efforts to boost Donald Trump’s campaign during the 2016 presidential election.

While the report detailed multiple contacts between Russian operatives and Trump associates during the campaign, investigators said they did not find evidence of a criminal conspiracy.

The Mueller report was not the first to warn of Russian meddling.

In January 2017, just two months after Trump was elected, the U.S. intelligence community reported that during the run-up to the election there had been a significant escalation by the Russians to interfere in U.S. domestic politics. The escalation was made possible by cyber-espionage and cyber-driven covert influence operations, the report said.

A year later, the Senate Intelligence Committee issued a report affirming intelligence agencies’ conclusion that Russia interfered with the 2016 elections to help Trump win. The Russian effort, senators concluded, represented an escalation in their ongoing attempts to attack U.S. democracy.

“Russian efforts to influence the 2016 U.S. presidential election represent the most recent expression of Moscow’s longstanding desire to undermine the U.S.-led liberal democratic order, but these activities demonstrated a significant escalation in directness, level of activity, and scope of effort compared to previous operations,” the report said.

Time-tested strategy

Russian efforts to influence U.S. elections are a time-tested strategy that can be traced back to at least 1964, when they sought to undermine Republican Barry Goldwater’s presidential campaign.

In 1983, the KGB undertook a massive campaign to discredit Ronald Reagan by labeling him a warmonger and arguing that re-electing him would be a grave mistake.

Re-elected the next year by a landslide, Reagan fought back. He increased the budgets of Radio Free Europe/Radio Liberty and then piped those stations’ broadcasts into the Soviet Union and Warsaw Pact countries.

He also supported opposition groups within the Russian sphere, such as the Solidarity movement in Poland, and initiated other efforts to counter the Russians’ activities, said Seth Jones, an international security expert at the Center for Strategic and International Studies.

“Moscow understood under Reagan that the U.S. was deadly serious about competing in this area,” Jones said.

That has not been the case under Trump.

Mueller's report notes that several advisers recalled that, after his election, Trump viewed stories about his Russian connections, investigations and the intelligence community assessment of Russian interference "as a threat to the legitimacy of his electoral victory."

His spokeswoman at the time, Hope Hicks, told investigators that Trump viewed the assessment of Russian meddling as his "Achilles heel" because people would think Russia helped him win.

Trump feared Mueller would 'end' his presidency:Mueller report takeaways

How they did it

During the 2016 election, the Russia employed tactics it has been using closer to home to sow discord among its democratic neighbors in the Balkans and to expand its influence.

Before Russia annexed Crimea from Ukraine in 2014, for example, it had launched a cyber campaign in eastern Europe. Russia flooded news web sites in Ukraine with tens of thousands of comments during unrest there, according to a report by the non-profit Rand Corp.

In the United States, the Russians bought $100,000 Facebook ads and bombarded Twitter accounts that boosted Trump and disparaged the Democratic candidate, Hillary Clinton. The Russians unleashed another weapon in their unconventional arsenal: cyber espionage, stealing emails and disseminating them to embarrass Democrats.

The Russian aim, according to Mueller’s report, was helping elect Trump because of a belief that it would benefit Moscow's interests.

“Although the investigation established that the Russian government perceived it would benefit from a Trump presidency and worked to secure that outcome, and that the Campaign expected it would benefit electorally from information stolen and released through Russian efforts, the investigation did not establish that members of the Trump Campaign conspired or coordinated with the Russian government in its election interference activities," the report concluded.

The Russian campaign actually began in 2014, according to the Mueller report, when the Internet Research Agency mimicked Americans on social media.

"Using fictitious U.S. personas, IRA employees operated social media accounts and group pages designed to attract U.S. audiences," the report says. "By early to mid-2016, IRA operations included supporting the Trump Campaign and disparaging candidate Hillary Clinton."

The report cited an anti-Clinton ad from March 2016 with a caption that read in part, "If one day God lets this liar enter the White House as a president – that day would be a real national tragedy."

The operations seized on social divisions and showed a clear bias toward Trump, said Young Mie Kim, a professor at the University of Wisconsin-Madison whose research analyzed 3,500 Facebook ads bought by Russia and released last year by the House Intelligence Committee.

"If the goal was to simply sow the division, then, you should see voter suppression targeting likely Trump voters including the promotion of Gary Johnson," Kim said in an email, referring to Johnson, the Libertarian Party candidate in 2016. "We found ZERO voter suppression targeting likely Trump voters."

More:What the Mueller report on the Russia investigation says about Vice President Mike Pence

Were they successful?

“At least in the short to mid-term, they were fairly successful in achieving a number of their objectives,” said Jones, who is an expert on Russian disinformation.

What the Mueller report made clear, Jones said, is “this was about trying to foment polarization in the U.S. before the election and has continued since and has surrounded major issues from the #MeToo movement to Black Lives Matter to gun control.”

The Russians wanted to weaken the U.S. because “they view a period of significant internal discord as weakening us both at home and overseas,” Jones said.

The benefit for them, he said, is that internal partisan discord can stall a range of U.S. domestic and foreign policy decisions, such as the withdrawal of U.S. troops from Syria and Afghanistan.

"This is much, much bigger than elections,” Jones said.

Not only were the Russians able to successfully exploit divisions that already existed in the U.S., they also were able to undermine the legitimacy of the electoral process, McFaul said.

“Millions of Americans have now questioned the legitimacy of President Trump, and that’s damaging to the United States and that is good for Russia,” he said.

More:Vladimir Putin's team doesn't like Robert Mueller's report on election interference, Trump

More:Trump repeatedly tried to impede the Russia probe, Mueller report said. Was it obstruction

'A lot of work to do'

What should the U.S. do to stop Russian from interfering in upcoming elections, including next year's presidential campaign?

Some steps already have been taken.

The U.S. has slapped sanctions on Russian individuals and entities for election meddling and cyberattacks. A federal grand jury in Washington also has indicted a dozen Russian intelligence officers for a concerted effort to hack into Democratic political organizations and release troves of stolen files.

But, “we’ve got a lot of work to do if we’re going to prevent this in the future,” McFaul said.

McFaul and other experts said the tech industry must act to quickly identify and report foreign efforts aimed at influencing elections. The U.S. intelligence community also must develop plans to help tech companies thwart disinformation campaigns and reduce opportunities to steal and publish confidential information, they say.

After the terrorist attacks on New York and Washington on Sept. 11, 2001, an independent, bipartisan commission did an exhaustive study on the circumstances that led to the strikes, including U.S. preparedness and the immediate response afterward. The commission made recommendations to guard against future attacks.

But the Russian election meddling hasn't triggered the same kind of coordinated response. Trump has yet to condemn Russia's actions and has on several occasions said he believes Russian President Vladimir Putin's denials.

Jones finds that alarming.

“The U.S. has to take this threat seriously at the presidential level, which it hasn’t,” he said.

“When was the last time the president made any kind of a notable speech highlighting Russian active measures and the need for a U.S. response? The president hasn’t said a word about it. He has been pretty silent.”

Window on Trump and his team:From Trump Tower to WikiLeaks, the key moments detailed Mueller report

Shadow over Trump:Can the president escape shadow left by Mueller report?