The year 2018 witnessed the largest trade war in decades. In March, the United States increased tariffs on aluminum and steel by 10% and 15% respectively. Canada, China, the European Union (EU), India, Mexico, and Turkey each retaliated with proportional tariff increases on U.S. goods. In the meantime, the trade disputes between the United States and China quickly escalated to a scale without precedent.
Li, Minghao; Balistreri, Edward J.; and Zhang, Wendong, "The 2018 Trade War: Data and Nascent General Equilibrium Analysis" (2018). CARD Working Papers. 605.