Ever since World War II, the United States and the United Kingdom have enjoyed a truly special relationship grounded in a shared commitment to a world order based on democracy, the rule of law, and free trade, among other commonalities. However, significant changes on both sides of the Atlantic–with Britain’s decision to exit the European Union and the election of Donald J. Trump as the president of the United States–have brought the partnership to a critical crossroads. Unfavorable domestic pressures faced by both leaders and diverging strategic outlooks are putting the US-UK “special relationship” to a test. In this issue brief, Dr. Foerster and Dr. Raymond outline the key elements of this unique relationship and provide their recommendations for strengthening the partnership that helps anchor the liberal international order.