Critical minerals are key inputs to clean energy technologies and play a fundamental role in the low carbon transition. China’s dominance in the midstream processing of the critical minerals value chain creates strategic leverage through export restrictions and supply chain control. This drives the proliferation of critical minerals policies to build a supply chain that excludes China (ex-China), yet their success remains uneven and uncertain. This paper develops a conceptual framework grounded in the economics and metallurgy of critical minerals processing to explain why China’s dominance persists. It identifies the transmission channels through which these policies affect the economic and financial viability of critical minerals processing projects. The framework shows that capability in mineral processing is accumulated through learning-by-doing, which requires the availability of feedstock, finance, a specialised workforce, secure demand, and stable prices to support a specific feedstock-to-qualified output route. The study finds that China deliberately built a policy ecosystem over several decades to meet these requirements and develop the processing capabilities it now possesses. The study also identifies the structural positions of Japan, the United States, and Australia along the critical minerals value chain, their respective binding constraints, and evaluates whether their critical minerals policies address these constraints. For these countries, the policy recommendation is to align state interventions on finance, demand at scale, shared testing and certification, and buyer qualification along priority feedstock-to-qualified output routes.