This book provides a comparative, neo-institutionalist approach to the different factors impacting state adoption of--or refusal to adopt--same-sex marriage laws. The now twenty-one countries where lesbians and gay men can legally marry include recent or longstanding democracies, republics and parliamentary monarchies, and unitary and federal states. They all reflect different positions with respect to religion and the cultural foundations of the nation. Countries opposed to such legalization, and those having taken measures in recent years to legally reinforce the heterosexual fundaments...