Editor’s Note: For over a decade, the Islamic State and its predecessors focused almost exclusively on Iraq, Syria, and their neighbors. The downing of the Russian airplane over the Sinai Peninsula and e...

Last Tuesday’s Wall Street Journal (November 10, 2015) carried a front-page story titled “Ukraine: Cyberwar’s Hottest Front.”

Editor’s Note: Cyber attacks and the appropriate response are new territories in national security. On the one hand, most attacks do little damage, and their perpetrators are often unclear. On the other ...