Syrian President Bashar Al-Assad paid a previously unannounced visit to Tehran earlier this month, meeting with his Iranian counterpart Ebrahim Raisi and Iran’s Supreme Leader Ayatollah Ali Khamenei.

 Assad’s May 8 visit was his second trip to Iran since the Syrian conflict erupted in 2011. It received a great deal of attention by international media and observers, who largely saw the engagement as mainly a sign of the continuation of the alliance between Damascus and Tehran. This theme was also underscored by both sides in the Iranian capital. Describing the Iran-Syria relationship as “vital,” Khamenei stressed that “we should not let it weaken.” Assad, in turn, described bilateral ties as “strategic,” saying they should “continue with strength.”

Beyond re-emphasizing the strategic nature of Iran-Syria relations, Assad’s visit carried five key messages to both domestic and foreign audiences...