Trade wars and tariff policies have become significant concerns impacting global trade and economic relations in the 21st century. This paper investigates the long-term effects of these policies on global trade and economic relationships between countries. Using historical and modern trade war scenarios, such as the US-China trade war, the study reveals that the disruption of global supply chains, financial market volatility, and the impact on specific sectors (e.g., agriculture) are some of the long-term consequences. Regarding the impact on economic relationships, the study highlights the creation of new trade agreements and diversification of trade partnerships as potential effects. The paper concludes that while national measures might yield short-term political and economic benefits, global prosperity requires cooperative and stable international trade policies.