From an FT editorial:
However, the Qataris’ intervention in Syria, while boosting the revolt against Assad, has also created confusion. The Saudis support the handful of secular rebel factions and Salafi groups fighting the Syrian regime. The Qataris, by contrast, are less discriminating over who they support, and work through the Muslim Brotherhood, which is anathema to Riyadh. As a result the Qataris and Saudis last year created separate and competing military alliances, a rivalry that has undermined the rebellion against Assad – and may have led to weapons ending up in the hands of jihadi militants.