Sectarian violence isn't ancient hatred erupting — it's produced by four variables: identity-group grievances, elite instrumentalization, the Saudi-Iran regional proxy war, and (decisively) state collapse. Bahrain and Yemen share the first three; only Yemen suffered state collapse, and only Yemen has escalating sectarian violence — the collapse is what turns tension into violence.

— In our words · Source: Explaining Sectarian Violence in the Middle East: A Comparative Study of Bahrain and Yemen (Breanna C. Strand)