Citizen responsibility for war in imperfect democracies

Are individual citizens of imperfect democracies morally responsible for unjust wars waged by their state? Moral responsibility for unjust wars involves both retrospective and social responsibility. Citizens of imperfect democracies are retrospectively responsible when they choose to vote for a leader they know will wage an unjust war. This situation may occur very rarely. For example, US citizens did not have this political option at the outset of the Vietnam and Iraq Wars. However, even when citizens are not retrospectively responsible they have the social responsibility to engage in collective action to address the harms unjust war causes.