Soviet agents were instructed to infiltrate party and campaign staffs in the United States in search of embarrassing information to leak to the press, while Soviet propagandists pushed a set of anti-Reagan story lines to the Western media. Ultimately, they failed to influence the election. President Reagan defeated Walter F. Mondale, winning 49 states. Margaret Thatcher, who was similarly targeted, also won re-election in a landslide.

What exactly has changed since then to make foreign propaganda far more dangerous today?

During the Cold War, most Americans received their news and information via mediated platforms. Reporters and editors serving in the role of professional gatekeepers had almost full control over what appeared in the media. A foreign adversary seeking to reach American audiences did not have great options for bypassing these umpires, and Russian dezinformatsia rarely penetrated.

While television remains the main source of news for most Americans, viewers today tend to select a network in line with their political preferences. Even more significantly, The Pew Research Center has found that two-thirds of Americans are getting at least some of their news through social media.

After the election, around 84 percent of Americans polled by Pew described themselves as at least somewhat confident in their ability to discern real news from fake. This confidence may be misplaced.

The sheer quantity of shares that misleading stories get on Facebook is staggering. Using a database of 156 election-related news stories that fact-checking websites deemed false, economists from New York University and Stanford University determined that these false stories had been shared by American social media users 38 million times in the three months before the 2016 presidential election.