Islamic State: Chechen Militants Outnumber Other Foreign Fighters, Experts Say

More than 15,000 citizens from 80 countries have joined the Islamic State in Iraq and Syria, estimates from U.S. intelligence indicate. Of these, one particular group has become especially prominent. Among high-ranking leaders targeted this week by the Obama administration was Tarkhan Tayumurazovich Batirashvili, a top Islamic State leader who has appeared in many of its social media posts and videos. Within the movement, he goes by the name Omar al-Shishani, which translates to "Omar the Cheche...