The Syrian regime’s main military ally, Russia, carried out airstrikes Sunday in the country’s southwest, defying a cease-fire pact with the U.S. and Jordan, as forces aligned with President Bashar al-Assad pushed to capture one of the last opposition strongholds.
The Russian strikes, which have been accompanied by regime barrel bombs and mortar shells, are the latest signs of the high-stakes military maneuvers unfolding in a volatile corner of southwest Syria. Forces aligned with President Assad have threatened a ground offensive,...