US-China Strategic Competition: Tariff Legitimacy, Trade Authority Constraints, and Manufacturing Overcapacity Disputes

Executive Summary

The Supreme Court's February 2026 tariff ruling has fundamentally shifted US trade policy execution while paradoxically strengthening America's negotiating position ahead of the Trump-Xi summit. The Court's 6-3 decision in Learning Resources v. Trump stripped presidential authority to impose tariffs under IEEPA, forcing the administration to pivot to alternative legal mechanisms. However, USTR's March 2026 Section 301 investigations targeting 16 economies for manufacturing overcapacity provide a more targeted and legally durable framework than the previous blanket approach. This tactical retreat has created strategic advantages: Xi enters the May summit believing he holds leverage over Iran and Taiwan, while Trump's new approach offers greater flexibility in trade negotiations through country-specific targeting .

Key Findings

1. Legal constraints have redirected rather than weakened trade enforcement capabilities

The Court of International Trade's May 7 ruling against Section 122 tariffs was temporarily stayed on appeal, but the underlying legal vulnerability remains . Section 301 investigations offer presidents greater flexibility to adjust tariffs country-by-country with stronger statutory foundations that have survived previous court challenges .

2. The timing convergence between legal setbacks and summit preparations creates negotiating asymmetries

Section 301 tariffs could be imposed by July 24, 2026, coinciding with the expiration of current Section 122 measures . Chinese officials view Trump's legal constraints as creating leverage for Beijing, particularly on Taiwan and trade concessions .

3. Manufacturing overcapacity investigations provide substantive economic justification for renewed trade measures

Evidence shows structural excess capacity leading to trade surpluses and underutilized US manufacturing, with Chinese overcapacity in steel reaching 54% of global excess capacity in 2025 . The investigations document specific sectoral imbalances, including automotive exports where the US accounts for 79.7% of Mexico's exports .

4. China perceives itself as holding superior leverage through multiple channels

China has tripled its use of export restrictions between 2021-2025, particularly in rare earth elements where it maintains a quasi-monopoly essential for US defense munitions . Beijing expects to extract Taiwan-related concessions in exchange for Iran cooperation .

5. The legal framework shift enables more sophisticated trade enforcement strategies

The administration's stated goal of using Section 301 tariffs to replace IEEPA measures suggests country-specific tariffs of similar magnitude but with enhanced legal durability . The broad scope of investigations covering both overcapacity and forced labor provides multiple justifications for trade actions .

Detailed Analysis

Legal Architecture Transformation

The Supreme Court's Learning Resources decision represents a constitutional inflection point in trade policy execution. The 6-3 ruling explicitly held that IEEPA does not grant presidential authority to impose tariffs, emphasizing that the statute's language does not include the distinct power to tax or raise revenue. This creates both immediate constraints and strategic opportunities.

The administration's rapid pivot to Section 122 authority proved legally vulnerable, with federal courts finding insufficient justification for balance-of-payments problems as required by the 1974 Trade Act. However, the Federal Circuit's administrative stay demonstrates ongoing appellate uncertainty, creating temporal windows for policy execution.

More significantly, the administration's deployment of Section 301 investigations reveals sophisticated legal adaptation. Unlike previous tariff authorities, Section 301 requires USTR consultation with target countries, providing procedural legitimacy while building evidentiary records. The investigations examine whether foreign practices are "unreasonable or discriminatory" and "burden or restrict U.S. commerce" — standards with established precedential support.

Manufacturing Overcapacity As Economic Justification

The Section 301 investigations construct a economic argument beyond traditional trade disputes. USTR documents that key trading partners have developed production capacity "untethered from domestic and global demand," leading to overproduction and persistent trade surpluses. This framing shifts from punitive tariffs toward correcting market distortions.

The scope encompasses 21 manufacturing sectors across 16 economies, demonstrating global rather than China-specific concerns. Evidence shows Chinese excess capacity driving global overcapacity, with China's steel production representing 54% of worldwide excess capacity in Q3 2025, up from 47% in Q3 2024. Similar patterns emerge in lithium-ion batteries, where Chinese production reached 1.9 times domestic demand.

The investigations document specific distortions affecting US industrial capacity. US manufacturing utilization reached 75.2% in late 2024, which USTR cites as evidence of domestic industry suppression by foreign overproduction. The mere existence of foreign structural overcapacity acts as an investment deterrent, preventing US firms from bringing new capacity online due to fears of being undercut by artificially low prices.

China'S Leverage Assessment And Strategic Positioning

Beijing's confidence entering the summit reflects multiple leverage points beyond trade volumes. China demonstrated export restriction capabilities last year after Trump's sweeping tariffs, announcing rare-earth restrictions that set the stage for negotiations and a one-year trade truce expiring this fall. Xi's weaponization of rare earth dominance during previous trade conflicts paved the way for the October 2025 Busan truce suspending the most punitive measures.

The Iran dimension adds geopolitical complexity to economic negotiations. Chinese officials view Trump's Iran conflict as weakening his position, with The Economist magazine capturing this dynamic with Xi observing Trump's difficulties. Washington understands it may need Beijing's help to nudge Iran back to negotiations, but seeking such support would moderate-to-high confidence give China the upper hand in bilateral relations.

Taiwan emerges as Beijing's primary strategic objective. Xi identified Taiwan as the most important issue for US-China relations, warning that mishandling would push the relationship to a "dangerous" place. Chinese officials may leverage Trump's apparent receptivity to similar arguments regarding territorial claims, following his approach to Russian positions on Ukraine.

Negotiating Leverage Asymmetries

The legal constraints paradoxically strengthen US positioning through several mechanisms. First, Section 301 authority provides country-by-country specificity and adjustment capabilities that blanket tariffs lacked. This enables targeted pressure while maintaining cooperative relationships with specific partners.

Second, the July 24 deadline for Section 301 decisions coincides with Section 122 expiration, creating temporal leverage for summit negotiations. Experts predict limited agreements involving tariff pauses, purchase commitments, or rare earth arrangements rather than trade deals.

Third, the evidentiary approach of manufacturing overcapacity investigations provides substantive justification transcending purely political trade disputes. The probe organizes around seven distinct policy interventions believed to create structural imbalances, representing a shift from narrow export subsidy focus toward broader industrial strategy analysis.

However, China's leverage operates across multiple domains. Washington's rare-earth vulnerability has intensified during the Iran conflict, as Defense Department munitions stockpile replenishment requires heavy rare earths where China holds a quasi-monopoly. China purchases over 80% of Iran's shipped crude exports, providing potential influence over Tehran while complicating US requests for cooperation.

Indicators To Watch

Decision Relevance

Scenario A (~45%): Limited summit agreements with Section 301 implementation — Recommended: prepare for targeted country-specific tariffs while maintaining diplomatic engagement channels. Companies should assess supply chain exposure to the 16 investigated economies and 21 specified sectors.

Scenario B (~35%): trade framework extending current truce — Recommended: monitor implementation mechanisms carefully, as previous agreements have proven fragile. Focus on sectors with demonstrated overcapacity vulnerability.

Scenario C (~20%): Escalation despite summit diplomacy — Recommended: activate contingency supply chain strategies immediately. The combination of legal constraints and Chinese leverage could produce unstable outcomes requiring rapid adaptation.

Analytical Limitations

• Summit negotiations are ongoing; real-time developments may significantly alter the assessment
• Section 301 investigation outcomes depend on public comment processes and inter-agency coordination not fully visible to outside observers
• Chinese internal decision-making regarding rare earth restrictions and Iran cooperation remains opaque
• Federal appeals court decisions on Section 122 authority could emerge without advance warning
• The interaction between multiple legal authorities creates unprecedented complexity in predicting enforcement mechanisms

Sources & Evidence Base

1. Comments to USTR Regarding Section 301 Investigations of Certain Economies' Structural Excess Capacity and Production in Manufacturing Sectors | Testimonies & Filings | Apr 15, 2026 | ITIF
2. Fact Sheet: USTR Initiates Section 301 Investigations into Structural Excess Capacity and Production in Manufacturing Sectors | United States Trade Representative
3. Court rules against the tariff Trump enacted after Supreme Court defeat
4. Federal Register :: Initiation of Section 301 Investigations: Acts, Policies, and Practices of Certain Economies Relating to Structural Excess Capacity and Production in Manufacturing Sectors
5. USTR Launches Awaited Section 301 Investigations Of 16 Economies For Manufacturing Overcapacity - International Trade & Investment - United States
6. Trump-Xi Summit 2026: U.S.-China Trade War Tensions and Tariff Talks - EconoTimes
7. Supreme Court tariff ruling boosts China's leverage before Trump-Xi summit
8. Trump's Board of Trade Move Signals the U.S. has Given Up on Changing China - The Wire China
9. U.S. Launches Section 301 Investigations into Global Manufacturing Overcapacity
10. USTR launches Section 301 hearings on global manufacturing overcapacity - Logistics Management
11. USTR Initiates Section 301 Investigations Relating to Structural Excess Capacity and Production in Manufacturing Sectors | United States Trade Representative
12. China's Xi expected to press Trump on Taiwan, tariffs during summit | Donald Trump News | Al Jazeera
13. Section 301 Investigations 2026: What Importers Need to Know | Fleischer Group
14. AAM to USTR: Section 301 Investigation into Industrial Overcapacity is Warranted - Alliance for American Manufacturing
15. Trump and Xi dialed down the trade war, but challenges lurk at their China summit - The Washington Post