Taylor Swift’s Eras Tour has come to an end, but the Taylor Swift Effect will remain a powerful force with influence well beyond even Swift herself. Often used to describe Swift’s economic impact through her fandom, it has become shorthand for the broader network effect that amplifies and extends the reach of her discography and cultural influence. As this article discusses, the Taylor Swift Effect has real implications for international relations and international law at a time when many nations are withdrawing from constructive international engagement, with devastating consequences in terms of global rights, liberties, and norms. This article explores the Taylor Swift Effect in the context of international law, beginning with the connection between Swift’s music and norms and principles of international law and expanding upon this foundation to consider broader applications. Just as international law has many smaller-scale layers to its generation and dissemination, the Taylor Swift Effect can turn how individual fans react to and internalize Swift’s music into global movements with the power for collective change. As Swift sings in New Romantics, “life is just a classroom,” and an assessment of where her discography and actions highlight the potential and shortcomings of international law is both insightful and overdue.