In recent weeks, officials inside Germany’s security agencies have been fondly circulating an article from the website of Foreign Policy magazine that was published on Aug. 3 with the headline, “Russian Hackers Can’t Beat German Democracy.” The article speculates about what Russia could do to disrupt the German federal election, which takes place on Sept. 24, and argues that the Russians will certainly attempt to interfere. Notably, though, the magazine concludes that the Kremlin is unlikely to succeed. Germany, the article argues, is excellently prepared for dealing with any attack because politicians and voters alike have been sensitized to the...