Foreign election interference: Is the U.S. prepared?

After the 2016 presidential election, major investigations were launched to understand the extent of Russia’s efforts to affect the outcome. The question of how much of an impact, if any, Russian meddling had on the result is a matter of debate. But intelligence officials have linked Russian actors to a sprawling influence campaign that included hacks of Democratic Party officials and a wave of fake news stories created by so-called troll farms with the goal of helping Donald Trump win the election.

Sanctions and criminal charges for dozens of Russian...