syria is a secular state ruled by a secular arab nationalist party, the ba'ath party.iran is an islamic republic. so they don't seem to be a marriage made in heaven. but it's a symbiotic relationship that's based on strategic necessity. >> it's not a particularly natural alliance, if you will. but for reasons of common enmity towards iraq, towards israel and other regions, they did form this alliance that has been the strongest, the most enduring in the region. >> narrator: but back in the early 1980s, while assad was building an alliance with the new shiite theocracy in iran, he was facing resistance from fundamentalist sunnis at home. >> there was a very aggressive islamic fundamentalist opposition to the syrian regime. there were attacks against the regime. it was essentially almost a civil war. (explosions) >> narrator: the assad regime's response was to attack the stronghold of syria's muslim brotherhood, the town of hama. >> in 1982, the syrian regime launched one of the worst massacres in the history of the middle east. the regime used artillery to level large p