This Peace Brief analyzes the regional sectarianism and dynamics related to the Syrian conflict. The Syrian conflict's internal dynamics have reshuffled regional alignments alongside unprecedentedly clear-cut sectarian dividing lines; this has often occurred against the preferences of regional state actors, including Saudi Arabia and Iran. Foreign states have generally adopted expedient policies that followed sectarian patterns for lack of alternatives. Iran bears significant responsibility for exacerbating the conflict's sectarian character at the regional level. There is no such 'diplomatic shortcut' to regional appeasement; it is the domestic Syrian deadlock that must be broken in order to alleviate sectarian tensions across the Middle East, not the opposite.