Even as Israel bombarded Syria, officials say the U.S. and Gulf countries were working to weaken its president’s alliance with Tehran. Rebels’ shock advance has dampened those hopes.

Fighters from Hezbollah and Iraq’s Shiite militias have deployed to Syria to support government forces, but it’s unclear if they are capable of turning the tide.

Iran will weigh sending troops to Syria if President Bashar Al-Assad requested such a move to stop a rebel advance that’s causing the biggest threat to his rule in years.

Iran is clearly trying to shore up support for the Assad regime after the regime suffered setbacks at the hands of Hayat Tahrir al-Sham, an opposition group.

Iranian foreign minister has said that the country is ready to send troops to Syria and is awaiting official request from president Bashar Al-Assad. This comes as Iran's ally Russia is already helping the government forces fight Hayat Tahrir Al-Sham rebels in Syria.