Tax Insights: Defence supply chains ─ Executive order strengthens US sourcing and supply chain oversight

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Issue 2026-28

In brief

What happened? 

On July 20, 2026, US President Donald Trump signed Executive Order (EO) “Securing America’s Defense Supply Chains and Ensuring Domestic Acquisition of Critical Materials.”¹ The EO tightens enforcement of 10 U.S.C. 4872 (the section 4872 restriction) — the statute restricting the Department of War (and other military department) contractors and subcontractors from using “covered materials” sourced from “covered nations” (i.e. geopolitical adversaries — this does not include Canada)² without a waiver.

The EO’s key provisions require:

• the Department of War (and other military departments) to generally cease, effective January 1, 2027, issuing waivers under the section 4872 restriction except where a contractor or subcontractor submits an accepted formal mitigation plan
• the Secretary of War (the Secretary) to develop:
  • within 180 dys, a policy requiring all prime contractors and subcontractors at every tier to map and “illuminate” critical supply chains, including submission of an “indentured Bill of Materials”³ tracing components back to raw material origin
  • within 90 days, a strategy to accelerate testing and qualification of domestic/allied material sources

Why is it relevant?

Although Canada is not a covered nation, this EO is relevant for Canadian businesses from a compliance and supply chain visibility perspective if they are involved with the US defence supply chain. Canadian suppliers of covered materials (e.g. magnets, tungsten, tantalum and molybdenum products) into US defence supply chains should expect increased documentation requests from US prime contractors, including support for “indentured Bill of Materials” submissions and vetting for foreign ownership, control or influence (FOCI) risk — particularly when a Canadian entity has ownership, financing or board ties connected to a covered nation, which could affect its “allied source” status regardless of its Canadian domicile.

Actions to consider

Organizations participating in the US defence supply chain should promptly identify their reliance on the section 4872 restriction waivers, assess replacement sourcing options and develop mitigation plans for transitions not completed by January 1, 2027. They should also map their supply chains for material origins, evaluate suppliers for financial and FOCI risks, and review contracts for compliance and potential exposure.

In detail

Background

The EO reflects the US Administration's broader strategy of strengthening domestic manufacturing capacity and reducing strategic dependence on foreign adversaries for critical defence inputs.

Historically, contractors have frequently relied on statutory waivers where compliant sources were unavailable or not commercially viable. Under the new framework, obtaining a waiver will require detailed documentation demonstrating exhaustive efforts to secure compliant alternatives, supported by a credible mitigation strategy and a defined implementation timeline.

This EO and a recent companion proclamation on incentivizing onshoring of aluminum production that was also signed by President Trump on July 20, 2026⁴ are also intended to increase the production of primary metals in the United States.

Waiver restrictions (effective January 1, 2027)

Starting January 1, 2027, waivers under the section 4872 restriction will only be issued when a prime contractor or subcontractor submits a formal mitigation plan that:

• identifies the specific source of the non‑compliant covered material
• documents exhaustive efforts to acquire compliant material or demonstrates that the compliant material was unavailable
• describes concrete steps to remove the non‑compliant material from the supply chain
• establishes a strict projected implementation timeline

The EO emphasizes that merely failing to qualify a US domestic source is insufficient to establish “non‑availability” — the contractor must show active, adequately funded and ongoing qualification efforts. This standard significantly raises the evidentiary bar for waiver applications.

Supply chain mapping and illumination requirements

Within 180 days of the EO (mid‑January 2027), the Secretary must develop a policy that requires contractors at all tiers to:

• submit an indentured Bill of Materials that traces all components, parts, equipment, software and materials to the origin of the raw materials
• vet all suppliers for three risk categories –– (i) financial risk, (ii) FOCI risk, and (iii) manufacturing and supply risk
• prohibit unreliable foreign suppliers (i.e. contractors may not use covered materials from persons subject to FOCI by a covered nation or otherwise designated by the Secretary)

The policy will also include post‑vetting obligations, such as implementing mitigation actions, notifying the Department of War of significant risks within 15 days, submitting a corrective action plan within 45 days, and filing a closeout report upon completion.

Enforcement and consequences

The EO establishes the following enforcement mechanisms:

• Contractors that fail to qualify alternative sources may face suspension of task orders, non‑exercise of contract options or termination of the contract.
• Fraud, deliberate misrepresentation or knowing/willful failure to implement a mitigation plan may result in contractual remedies and referral to the Attorney General.
• The Secretary is required to report semi‑annually to the Assistant to the President for National Security Affairs until January 1, 2028 to keep the executive branch apprised of the progress made on the enhanced compliance procedures.

Enforcement exceptions

The EO does not apply to the US Strategic Critical Minerals Reserve (also known as “Project Vault”), or to acquisitions from:

• foreign projects financed by the Export‑Import Bank of the United States or the U.S. International Development Finance Corporation, or
• companies receiving grants, financing or support from the Departments of State, War, Commerce or Energy

Next steps for businesses

Businesses involved in the US defence supply chain should:

• audit their section 4872 restriction waivers – Inventory all current and anticipated reliance on the section 4872 restriction waivers. For each, determine whether the underlying material can be sourced from a compliant supplier by January 1, 2027.
• prepare a mitigation plan – Where compliant sourcing is not immediately feasible, begin drafting a mitigation plan that meets the four required elements. Plans should include credible qualification timelines supported by documented funding commitments.
• analyze their Bill of Materials – Initiate indentured Bill of Materials development across the supply chain that traces to origin of the raw materials. This is a significant data‑gathering exercise that may require months of sub‑tier engagement.
• assess their supplier risk – Implement or enhance supplier vetting programs covering financial risk, FOCI risk and manufacturing/supply risk — the three categories explicitly required by the EO.
• qualify their domestic sources – Identify domestic or allied‑nation alternative sources for adversary‑sourced materials and initiate qualification testing. Document all efforts to demonstrate “active and adequately funded” pursuit.
• review their contracts –– Review existing government contracts for flow‑down obligations, compliance certification requirements and potential termination exposure.
• coordinate across all business functions – Engage procurement, legal, export controls, government contracts, tax and finance teams. The compliance scope (i.e. all tiers, three risk categories, 15‑day notification, 45-day corrective action) requires enterprise‑wide coordination.

The takeaway

The EO significantly elevates expectations for supply chain transparency and sourcing compliance across the US defence sector, and will affect Canadian businesses that are subcontractors or supply covered materials to the US defence supply chain. With waiver availability expected to narrow substantially beginning January 1, 2027, and comprehensive supply chain mapping requirements anticipated within the next six months, affected organizations should move quickly to assess current exposures, strengthen supplier oversight and develop actionable transition plans.

Early preparation will be critical to preserving contractual continuity, managing compliance risk, and positioning organizations for an increasingly resilient and security‑focused procurement environment.