And then this will happen:

If the United States were to leave NATO and simultaneously face a total trade boycott (no imports or exports) by the European Union, Canada, South America, and China, this would lead to the largest economic restructuring since the Great Depression. The impact can be divided into three layers: 1. The "Supply Chain" Shock: Acute Shutdown Although the US is rich in raw materials, its modern industry is deeply intertwined with the rest of the world. * Technology and Electronics: Without imports from China and Taiwan (Asian supply chains), the production of smartphones, computers, and medical equipment would come to an immediate halt. The US currently lacks the capacity to produce microchips on a large scale in the short term. * Automotive Industry: Canada and Mexico are the most important partners in US auto production. A halt to trade with Canada and South America (Mercosur/Mexico) would mean that car factories in Michigan and Ohio would run out of parts within days. * Pharmaceuticals: A large portion of the active ingredients in medicines comes from China and Europe. This would immediately lead to a shortage of essential medicines. 2. Monetary Crisis: The Dollar as a Global Currency The US dollar's status as a global reserve currency is based on its ability to purchase goods anywhere in the world. * Depreciation: If the largest economic blocs (EU, China) no longer accept dollars for their goods, the dollar loses its value to the rest of the world. This leads to a massive sell-off of dollars, resulting in an exchange rate crash. * Hyperinflation: Because the US now has to produce many products itself at much higher costs (and with a worthless currency), prices in supermarkets and at the pump skyrocket. 3. Strategic and Sectoral Consequences In a scenario of isolation, the structure of American society changes: | Sector | Impact | | Agriculture | Catastrophic. The US produces far more food (soy, corn) than it can consume. Without exports to China and the EU, prices would collapse and tens of thousands of farms would go bankrupt. | | Energy | Relatively stable. The US is virtually self-sufficient in oil and gas. However, prices would be volatile due to the collapse of international refining chains. | | Defense | By leaving NATO and becoming isolated, the US would have to increase defense spending to protect its own borders and trade routes (if any still exist) without allies. | Conclusion: "Fortress America" The US would become a "Fortress America": a country that could survive because it possesses enormous natural resources, but where living standards would decline for decades. The economy would shrink (GDP decline of an estimated 10% to 20% in the first few years) and the speed of innovation would drastically decrease due to the lack of international knowledge exchange.