March–April 2026
The Substitution Clock
Measure whether technology controls create a usable strategic advantage.
Memo 02 · GitFlash Memos · GitFlash · Retrospective thematic edition · Prepared 6 September 2026 · Published 7 September 2026
10 pages · approximately 12 minutes · Research cutoff 6 September 2026
The decision question
What must a technology control change before substitution or coalition fatigue closes the window?
A decision memo on judging controls by the capability they delay, the time they create and how that time is used.
Preview
A restriction can impose cost without changing the outcome that matters. The review must start with one function, one purpose and one counterfactual.
This memo connects substitution, partner implementation and domestic delivery to a bounded retain, narrow, expand or replace decision.
Contents
- Separate constraint, coercion and signal
- Map the three boundaries of a usable window
- Read the semiconductor case through functions
- Four policy choices
- A 90-day review that can change the rule
Takeaways
- Measure a function, not a national chip total.
- Hold the policy purpose fixed while judging results.
- Use any time gained to deliver a defined capability.
Sources
- 1. Commerce Strengthens Export Controls to Restrict China’s Capability to Produce Advanced Semiconductors for Military Applications
Bureau of Industry and Security · 2 December 2024
Historical announcement of controls, scope and stated objectives. It does not establish achieved capability delay or describe the entire current rulebook.
- 2. Commerce Implemented Advanced Semiconductor Rules and Took Steps to Address Compliance Challenges
U.S. Government Accountability Office · 2 December 2024
GAO-25-107386. Rule development, interagency roles and reported compliance challenges; not a causal impact evaluation.
- 3. Mapping the Semiconductor Value Chain
Organisation for Economic Co-operation and Development · 24 June 2025
Original mapping of industry segments, cross-country dependencies and concentrated inputs. Concentration is not identical to political control.
- 4. U.S. Department of the Treasury Releases Sanctions Review
U.S. Department of the Treasury · 18 October 2021
An official historical evaluation framework for sanctions. Financial sanctions and semiconductor export controls are distinct instruments.
- 5. Export Controls on Advanced Semiconductor Manufacturing Equipment to Be Tightened
Government of the Netherlands · 15 January 2025
Announcement of additional national authorization requirements from April 2025. Evidence of a separate jurisdictional decision.
- 6. Annual Report 2025
ASML · 2026
Company disclosure of export-control exposure and commercial risks. Management statements do not independently establish policy effects.