“The four countries that make chips possible have agreed—quietly—not to make them possible for China.” The Chip 4 Alliance is an informal technology coordination group comprising the United States, Japan, South Korea, and Taiwan, designed to align export controls, supply chain policies, and semiconductor investment strategies to prevent China from accessing cutting-edge chip manufacturing capabilities.
Executive Summary
Proposed by the United States in 2022, the Chip 4 framework brings together the four economies that collectively control the entire advanced semiconductor value chain: the U.S. (design software, IP, chip architecture, equipment); Japan (specialty chemicals, photoresists, equipment); South Korea (memory chips, display technology, logic fabrication); and Taiwan (TSMC’s foundry dominance at the leading edge). Unlike formal treaty alliances, Chip 4 operates through bilateral coordination, aligned export control regulations, and investment screening policy harmonization rather than a formal secretariat or binding agreement—giving member governments diplomatic flexibility while achieving strategic alignment.
The Strategic Mechanism
Chip 4 exerts control over the semiconductor supply chain through five chokepoints:
- Design software (EDA tools): U.S. companies Cadence, Synopsys, and Mentor Graphics dominate electronic design automation—no advanced chip can be designed without their tools, and all are subject to U.S. export controls.
- Manufacturing equipment: U.S. Applied Materials, Lam Research, and KLA, combined with Japan’s Tokyo Electron and Netherlands’ ASML (coordinated through U.S. pressure), control the equipment supply for every advanced fab globally.
- Specialty chemicals and materials: Japan supplies 90% of global photoresist and a dominant share of semiconductor-grade specialty gases—materials subject to Japanese export controls aligned with U.S. policy.
- Logic and memory fabrication: TSMC (Taiwan) produces over 90% of chips below 5nm; Samsung and SK Hynix (South Korea) dominate DRAM and NAND memory—giving the alliance de facto control over advanced chip supply.
- Chip architecture IP: ARM (U.K., with U.S. OFAC jurisdiction) and U.S. firms hold foundational patent portfolios that constrain any nation’s ability to design competitive chips outside the alliance’s IP architecture.
Market & Policy Impact
- China’s indigenous response: Chip 4 coordination has accelerated China’s semiconductor self-sufficiency drive—CXMT in memory, SMIC in logic, and Huawei’s HiSilicon in design—with China committing over $150 billion in state semiconductor funding through 2030.
- South Korea’s strategic tension: Seoul faces the sharpest Chip 4 dilemma: China is South Korea’s largest export market and home to major Samsung and SK Hynix fab investments—making full alignment with U.S. export control postures economically costly.
- Taiwan’s existential stakes: TSMC’s centrality to the global chip supply chain makes Taiwan simultaneously the alliance’s most valuable member and its most geopolitically vulnerable—a dynamic that shapes U.S. deterrence posture toward China in the Taiwan Strait.
- Japan’s strategic re-entry: Japan has leveraged Chip 4 to re-establish semiconductor industry relevance through Rapidus (a state-backed advanced fab targeting 2nm production by 2027) and expanded export controls on 23 categories of semiconductor manufacturing equipment imposed in 2023.
- Allied friction management: The U.S. has had to offer investment incentives (CHIPS Act carve-outs, diplomatic assurances) to maintain South Korean and Japanese alignment, revealing that the alliance requires continuous maintenance to prevent economic incentive defection.
Modern Case Study: Japan’s 2023 Export Control Alignment and ASML’s EUV Restrictions
In March 2023, Japan announced export controls on 23 categories of advanced semiconductor manufacturing equipment, directly aligning with the U.S. October 2022 BIS rules. Simultaneously, the Netherlands—under sustained U.S. diplomatic pressure—confirmed that ASML would not be permitted to ship EUV lithography machines to China, extending the restriction it had applied since 2019 to include deep ultraviolet (DUV) immersion systems in 2023. These coordinated moves—involving three of the four Chip 4 members plus a fifth aligned partner in the Netherlands—demonstrated that the alliance’s informal coordination mechanism could produce synchronized national export control regimes affecting the entire manufacturing equipment supply chain. China’s Ministry of Commerce formally protested and accelerated domestic equipment development, but no Chip 4 member reversed its controls. The episode established Chip 4 as a functional, if informal, allied technology denial coalition with demonstrated enforcement capability.