Highlights :

• Between January 2025 and March 2026, the U.S. average applied tariff rose sharply, reaching more than 15% by March 2026.
• Under sustained policy uncertainty, the legally durable instruments — such as Section 232 — captured a rising share of aggregate protection and came to dominate the residual structure once the emergency IEEPA layer was removed.
• A counterfactual general-equilibrium analysis indicates that a legally durable Section 301 regime could approximate the tariff regime in force in November 2025, on the reindustrialisation objective, without recourse to legally fragile emergency instruments.
• The resulting gains in manufacturing value added reflect a sectoral reallocation achieved at an aggregate cost — U.S. GDP declines — while the cross-country incidence is governed as much by instrument design as by the average tariff level.

 Abstract :
This paper asks how a legally durable tariff regime could reproduce the "ideal" structure that the second Trump administration had assembled by November 2025 high, country-differentiated tariffs combining Section 232 protection, IEEPA reciprocal tariffs and framework deals — after the Supreme Court struck down the IEEPA tariffs in February 2026. From a product-level database of every U.S. tariff action of 2025–2026, I distinguish each statutory instrument and assess five configurations through counterfactual general-equilibrium analysis, measuring how far each realistic, durable regime stands from that November 2025 target and through which instrument the administration could return to it. Every configuration lowers U.S. GDP (by 0.37 to 1.37%) while improving the terms of trade; but on the metric tied to the stated objective — the reindustrialisation of manufacturing — a prospective, legally durable Section 301 regime can produce similar results to those of the target, raising U.S. manufacturing value added by +3.6% against +4.4% for the November 2025 hybrid and +1.9% for Section 232 alone. Instrument design — coverage breadth and partner targeting — matters as much as the average tariff level for the cross-country incidence, targeted Section 301 tariffs creating winners among non-targeted economies while broad-based configurations produce near-universal losses.

 Keywords : Trade Policy | Tariffs (Sections 232, 301, IEEPA) | Computable General Equilibrium | Reindustrialisation | Trade Diversion

 JEL : F13, F17, C68