Beyond the growing number of militant recruits in Europe, extremist groups in Libya, Afghanistan, Nigeria and the Sinai have declared their allegiance to the Islamic State, which has also reportedly put down roots in Southeast Asia.
But what many view as a leadership vacuum is most acutely felt in the case of Syria. In response, Saudi Arabia and Turkey, with an assist from Qatar, recently ended a long estrangement to address their shared concern over the lagging fight against Assad.
The new approach could undermine three years of U.S. Syria policy focused on securing a negotiated settlement to the war by putting enough pressure on Assad that he feels compelled to make compromises, but not enough to score an outright opposition victory that might result in chaos and cause Syria to collapse even further.
Most of the moderate groups chosen to receive support have been eliminated or eclipsed by extremists, however, and the negotiation process begun years ago in Geneva has languished.
