Every US Quantum Computer Runs on Foreign Parts and Foreign Inventions

Table of ContentsIntroductionA Note on AttributionThe Discovery Layer: Theory and AlgorithmsSuperconducting QubitsTrapped IonsOther ModalitiesQuantum Error CorrectionThe Enabling StackQuantum Networking and CommunicationsPost-Quantum CryptographyThe ScorecardWhy This Matters for PolicyWhat America Actually Built

Introduction

Spend enough time at quantum conferences, in board advisory sessions, or reading popular science coverage of quantum computing, and you will hear some version of the same story: quantum computing is an American invention, built on American physics, scaled by American companies, and now defended by American policy. The narrative shows up in conference keynotes (usually during the slide about Feynman), in investor pitches (“the U.S. leads in quantum”), in policy documents, and in casual conversation at every quantum industry event I have attended in the past five years. It is the water the U.S. quantum community swims in. Most of the people repeating it have never stopped to check it.

The most recent and most specific version came from Paul Dabbar. After the White House Summit on American Quantum Innovation on July 7, Dabbar wrote on LinkedIn: “The arc of the last decade, and the shape of the decade ahead, is this: America built every layer of the quantum stack one at a time, across a century, largely without knowing it was building a stack.” He described a “discovery layer” that was “built by physicists who were asking questions that had no commercial application.”

I single out Dabbar’s version because it is testable. He makes a specific, attributable claim about a specific thing (the quantum stack), with a specific scope (every layer), over a specific period (a century). That is a claim I can check.

Dabbar’s own list of layers includes discovery, culture, talent, capital, standards, industrial capacity, and markets. What follows does not pretend that those categories are identical to a technical stack. It tests th…