In the final days leading to his ouster, Syrian President Bashar al-Assad complained to Iran's foreign minister that Turkey was actively supporting Sunni rebels in their offensive to topple him, two Iranian officials told Reuters this week.

The Bashar al-Assad regime’s rapid collapse deals a heavy blow to Iran’s “axis of resistance” and its ability to project power in the region, and it raises fears Iran will focus more on developing its nuclear program.

The leaders — from Egypt, Jordan, Saudi Arabia and the United Arab Emirates — are worried that Assad’s ouster could stir unrest at home, say analysts, officials and diplomats. They are also concerned that Syria could plunge into chaos,