BEIRUT (AP) — Here’s a list of key fighting groups inside Syria:

— SYRIAN GOVERNMENT — Despite major defections early in the conflict and the loss of significant territory to rebels, the Syrian military remains a potent force against an outgunned opposition. President Bashar Assad’s inner circle has largely remained cohesive and united, avoiding high-level defections that would sap its strength. The military has successfully exploited its greatest advantage, its uncontested airpower, to pound opposition-held areas and sustain far-flung bases holding out in rebel territory. Assad has bolstered his overstretched military over the past year with the creation of the National Defense Force, a pro-government militia that draws heavily from Syria’s minority communities and reportedly receives training from Iran.