Realistically, global trade drying up. Canada, Mexico, the EU, and others just refusing to do business with the US. Or possibly, making deals on a state-by-state basis, such as exchanging with California and New York, while ignoring Texas. By doing something like that, foreign nations can help prop up anti-conservative states, while bleeding conservatives lily white.

Mutual military agreements, such as retooling NATO to exclude the US and incorporating Canada, Mexico, and Taiwan might happen as well. The US has ceded their mutual exchange with Taiwan, other powers like India would like to have those chips. Maybe the EU outright allying with Ukraine, to remove Russia from play and to secure Ukraine’s grain, oil, and expertise on warfare.

…In short, it will be a couple decades of work to stop the Turdpublican agenda through diplomatic pressure. Probably around a decade if WW3 or a 2nd American Civil War happens.