Strategypage writes about the potential problem of jihadis fleeing Iraq and ending up in Syria:
Although active against the Iraqi Security Forces and coalition troops, Syria is well aware that groups like al Qaeda are frequently just as dangerous to secular Muslim countries as they are to infidels (non-Moslems). Syria, although Moslem, is officially a secular nation and has become increasingly corrupt, incompetent, and autocratic over the last 30 years. All these factors are fertile ground for Islamic terrorism and uprising, which groups like al Qaeda specialize in exploiting to gain more recruits and support. The Syrians realize all this could be a major problem in the future.
Al Qaeda, of course, considers Israel an enemy, but it's much easier for terrorists to operate and strike in countries with popular domestic discontent, corrupt officials, and secular governments. In other words, countries like Syria.
Blowback isn't just something that happens to America.