- The costs are greater the deeper the trade fragmentation. - Reduced knowledge diffusion due to technological decoupling is a powerful negative amplifier of the trade channel. - Emerging markets and low-income countries are most at risk from trade and technology fragmentation. - Transition costs can be considerable, in some cases even exceeding the final trading impact. - The estimates provided are not the upper bound. The G20 might not address issues of national security directly, but there's much they can do, especially regarding the trade-offs between resilience and efficiency, designing policies to avoid resorting to the least discretionary breadth.