Trade will continue as before between all actors. What's going on is that great powers are wary of sourcing smart things that can be turned off or reprogrammed

Trade will continue as before between all actors. What's going on is that great powers are wary of sourcing smart things that can be turned off or reprogrammed remotely (think OTA updates) from other great powers. So trade in these smart things is shakier. It was good before when we ignored the issue! As more products become smart things, this will impact trade somewhat. For the smaller countries, there's no change from the atomic era: they'll source their smart thing from their protector power. There's a lot of friction getting there though, as many of them defected and sourced from a cheaper alternative.