Recently, policy makers have taken a deep interest in global value chains (GVCs), with a view to making them more resilient and robust in most countries’ post-pandemic recovery plans. A central assumption in all policy proposals seems to be that the classic GVC is the relevant unit of analysis: each “lead” firm organizes a pipeline of suppliers (its supply chain) as needed to produce a good or service. In such conventional GVCs, it is easy to identify the critical inputs and bottlenecks that create vulnerability to disruption. But in industries characterized by what we call “massive modularity”, this becomes extremely difficult.