Chapter 4 picks up again on the reasons for international trade conflicts, using the Stolper-Samuelson theorem to explain competing specific national interests, and the optimal tariff theory and the Hicks theorem to explain competing short-term national interests. The chapter then provides a comprehensive economic analysis of the US-China trade war that erupted in 2018, framing the conflict through the lenses of competing national interests—overall versus specific, and long-term versus short-term. The chapter concludes that the underlying drivers of the trade war are rooted in the US strategic objective to curb the development of China's high-tech sector, thereby protecting its monopoly profits, slowing China's industrial upgrading, and maintaining US global economic dominance, even though the tariff measures have largely failed to improve US welfare or its trade balance.