As Washington celebrates tactical wins against Islamic State affiliates in Nigeria, Americans should demand policymakers pause. What began as advisory support, intelligence sharing, and targeted strikes now risks expanding across the Lake Chad Basin. Americans should...

Allies and clients have frequently entangled their great power patrons in needless geopolitical crises and sometimes even bloody wars. The tragic events leading to World War I in 1914 are a classic example. Serbia helped drag Czarist Russia into that bloody maelstrom...