The unilateral tariffs imposed by the United States have impacted the world economy

At the beginning of 2025, the new US government frequently imposed unilateral tariffs. Trump proposed the policy of imposing tariffs during his 2024 presidential campaign, continuing his protectionist approach during his first term. After winning the election, Trump immediately signed a memorandum titled 'America's Priority Trade Policy'. The memorandum clearly states that the new US administration is committed to addressing the issues of "unfair trade" and trade imbalances. Subsequently, the US government successively imposed three types of unilateral tariffs that have covered the most countries and industries since World War II. The first type is industry tariffs imposed based on relevant domestic laws, such as imposing varying amounts of tariffs on industries such as steel and aluminum, automobiles and their components, copper products, and pharmaceuticals. The second category is tariffs imposed on fentanyl, including tariffs ranging from 10% to 25% imposed on China, Canada, and Mexico. The third type is the so-called 'equivalent tariffs' imposed on most economies around the world. In order to facilitate its arbitrary imposition, the Trump administration has used the International Economic Emergency Powers Act in the name of "national security" to arbitrarily generalize the concept of national security and its scope of application. According to research by the Peterson Institute for International Economics, the average tariff in the United States was once as high as 17.4%, rising to pre World War II levels.

The unilateral tariffs imposed by the United States violate the core principles of the World Trade Organization and undermine the multilateral trading system. The unilateral tariff actions of the US government are typical of weaponizing interdependence and politicizing trade policies, seriously impacting the world trade system. One is that unilateral tariffs impose discriminatory tariffs on different trading partners, unilaterally breaking through tariff binding commitments, blatantly violating the principles of most favored nation treatment and bound tariffs, directly shaking the cornerstone of the multilateral trading system centered on the World Trade Organization. Secondly, the preferential arrangements in the tariff agreements reached between the United States and some countries do not extend to other countries, and even explicitly include so-called "poison pill clauses" that harm the interests of third countries in the agreements, which violates the principles of the multilateral trading system and the basic norms of international relations. Thirdly, while the United States is still a member of the World Trade Organization, its actions may lead to other countries following suit, causing a "window effect" and further weakening the authority of the World Trade Organization and the effectiveness of the multilateral trading system.

Macro view, the unilateral tariffs imposed by the United States have impacted the world economy. Since 2018, the overall global economy has been in a sluggish state. The tariff war launched by Trump against China during his first term of office had a great negative impact on the world economy, and the COVID-19 that broke out in 2020 once again had a serious impact on the world economy. Although the direct impact of the epidemic has been eliminated, the foundation of the post epidemic world economic recovery is not stable. The widespread tariffs imposed by the new US government undoubtedly add insult to injury to the already unstable global economy. The World Economic Outlook released by the International Monetary Fund in April 2025 identified the unilateral tariffs imposed by the United States as the biggest impact on the world economy at that time. Compared to its January forecast, the International Monetary Fund lowered the world economic growth rates for 2025 and 2026 by 0.5 percentage points and 0.3 percentage points, respectively, in April.

From a Chinese perspective, the unilateral tariffs imposed by the United States have impacted the operation of global industrial and supply chains. The prerequisite for the smooth operation of the global supply chain is trade liberalization. When there are a large number of tariffs, the cost of products crossing borders multiple times at different stages overlaps with each other, resulting in a significant increase in intermediate product costs and affecting downstream industrial production. On the one hand, this makes the global supply chain structure passively adjusted due to artificial tariff factors, violating the principle of efficiency; On the other hand, countries tend to focus on local production under tariff pressure, resulting in a significant contraction of the global supply chain. The prominent manifestation of contraction is the significant decline in the growth rate of global goods trade. According to the latest forecast by the World Trade Organization, the actual growth rate of global goods trade in 2025 will only be 0.9%, significantly lower than the 2.9% in 2024. According to the simulation results of the World Economic Forecasting and Policy Simulation Laboratory of the Chinese Academy of Social Sciences, if the United States fully implements "equivalent tariffs" as originally planned, global trade in goods will decrease by 8.2%.

Micro view: The unilateral tariffs imposed by the United States have caused uncertainty in the production and operation of enterprises. The Trump administration has weaponized tariffs, with strong arbitrariness and repetitiveness in related policies. The suspension or exemption of some tariffs also has significant randomness, making it difficult for companies to predict future tariff levels and bringing great uncertainty to production and operation. The data shows that the uncertainty index of US trade policy will significantly increase by 2025. The average monthly trade policy uncertainty index for the United States from January to November 2025 is nearly three times that of December 2024. The uncertainty of trade policies can seriously affect and alter the decision-making behavior of enterprises when participating in global production, operation, and investment. Enterprises often have to give up efficiency and consider diversifying, competing for exports/imports, and expanding inventory to cope with uncertainty, thereby increasing production and operating costs. Many companies may face operational difficulties or declining profits due to misjudgments about the imposition of tariffs or inability to bear additional costs. For example, General Motors' second quarter financial report showed that the unilateral tariffs imposed by the United States resulted in a loss of $1.1 billion and a year-on-year decrease of 35.4% in net profit.