Military withdrawal rather than total economic isolation

The scenario assumes the United States retreats from standing diplomatic and military commitments, not that it instantly disconnects from the world economy. Modern high-technology goods and weapon systems depend on international components, while American firms would still have incentives to sell abroad. Rebuilding self-sufficient supply chains would take far longer than the five-year horizon used here. The sharper shock is therefore the loss of forward presence, alliance guarantees, and the mass that American forces contribute to coalition operations.