The White House has unveiled a series of measures aimed at fortifying U.S. defense supply chains and addressing what it describes as discriminatory trade practices by Canada. These actions, announced on Monday, include an executive order and multiple proclamations that target critical materials, aluminum production, and various imports from Canada.

The administration’s strategy focuses on reducing dependencies on foreign adversaries for essential materials while promoting domestic production. These initiatives are part of a broader effort to ensure national security and economic stability in the face of global trade challenges.

Strengthening defense supply chains

The executive order titled “Securing America’s Defense Supply Chains and Ensuring Domestic Acquisition of Critical Materials” introduces stricter regulations on waivers that allow defense contractors to use materials from certain countries. Starting January 1, 2027, the secretary of war and military department secretaries will generally cease issuing such waivers unless contractors submit approved mitigation plans demonstrating efforts to shift to domestic or allied sources.

This order also mandates comprehensive supply chain mapping for critical national security acquisitions, including detailed bills of materials that trace components back to their raw material origins. It directs regulatory action to accelerate the qualification of domestic sources and requires reporting on implementation every six months until 2028.

The order emphasizes the need to secure supply chains against physical, cyber, and economic threats to maintain U.S. military dominance. It highlights the historical under-prioritization of domestic production and resilience by defense contractors, despite longstanding prohibitions on using sensitive materials from geopolitical adversaries.

Boosting domestic aluminum production

A separate proclamation strengthens Section 232 tariffs on aluminum imports to address national security threats. It establishes an incentive program for companies investing in new, expanded, or refurbished U.S. primary aluminum production facilities. Approved onshoring plans would allow importers to bring in primary aluminum at half the applicable Section 232 tariff rate corresponding to anticipated domestic output.

The Commerce Department will monitor compliance, with potential rescission of benefits, including retroactively in cases of fraud, for failure to meet commitments. This move aims to boost insufficient domestic primary aluminum supply, which is critical for military systems and other strategic uses.

Retaliatory tariffs on Canadian imports

President Trump also signed three proclamations under Section 338 of the Tariff Act of 1930 imposing additional 50% ad valorem duties on specified Canadian goods, effective August 19, 2026. These tariffs target discrimination in dairy, particularly cheese tariff-rate quotas favoring the EU over the U.S., motor vehicles, and alcoholic beverages.

The White House highlighted the economic impacts, including sharp declines in U.S. exports to Canada: motor vehicles down about 22%, alcoholic beverages down 81%, alongside lost opportunities for dairy producers. The tariffs apply in addition to other duties but exclude certain categories like energy, potash, and Section 232 goods.

These actions are designed to offset burdens on U.S. commerce and may encourage Canada to end the practices. The measures build on prior Trump administration efforts using Section 232 and other authorities to protect domestic industries, including previous adjustments to aluminum, steel, and other imports.

The Commerce Department and Customs and Border Protection will implement the tariff changes through modifications to the Harmonized Tariff Schedule. These initiatives are part of an “America First” trade policy promoting reciprocity and strengthening the U.S. industrial base.