From Escalation to Section 338

1. March 2025Canadian provinces and territories restricted U.S. alcoholic beverages as the tariff conflict expanded; Canada imposed counter-tariffs on U.S. products.
2. April 2025Canada implemented vehicle countermeasures tied to U.S. Section 232 automobile duties.
3. September 1, 2025Canada removed many broad counter-tariffs while retaining major steel, aluminum, and automobile measures.
4. February 20, 2026The Supreme Court held in Learning Resources that IEEPA does not authorize presidential tariffs.
5. July 1, 2026The United States declined to extend USMCA in its current form. The agreement remained in force and moved into annual review.
6. July 20, 2026Proclamations 11046, 11047, and 11048 invoked Section 338 and announced additional duties after the statutory waiting period.
7. August 18, 2026Proclamation 11056 moved the effective date to August 22 during negotiations.
8. August 22, 2026The U.S. duties entered into force. In official remarks, Prime Minister Carney announced a dollar-for-dollar Canadian response expected to take effect September 8, with the detailed tariff schedule still to be published.

What to monitor next

Controlled publication labels

IN FORCE

An operative legal measure with an effective date that has arrived.

ANNOUNCED

A stated future action without a final or effective legal instrument.

CHALLENGED

A filed legal challenge; do not imply relief unless a court grants it.

SUSPENDED

An action temporarily halted by a controlling instrument or court order.

EXPIRED

A measure that ended by its terms or by later authority.

Public education and legal research only. Tariff liability depends on classification, origin, entry date, valuation, content rules, exclusions, foreign-trade-zone status, and later official guidance. Verify the current HTSUS and customs instructions before operational reliance.