Diminished support for the Syrian government from Iran, Hezbollah, and Russia has allowed opposition forces to seize new territory and shift the balance of power. Rebels have captured almost all of Aleppo and now control a broad stretch of land in the west and northwest of the country. The vulnerabilities of President Bashar al-Assad's coalition have been exposed, with weakened allies and a lack of support. The weakening of Iran, Hezbollah, and Russia, along with a shift in Turkey's position, has created the conditions for the rebels' successful offensive.