I'm saying I would prefer it if their governments didn't have the ability to limit who their citizens can trade with, yes.

They have that ability through the power vested in them by the citizens, to effectively project the force that the citizenry, as a whole, desires to project.

If the citizenry cared, they can do something about that. (They don't, for a lot of reasons. And they're wrong, but they don't.)

If the government acted for the citizenry as a whole, then they wouldn't have to ban these transactions. At best, the government imposes the majority view on the minority. I think that in general this is more dangerous than helpful. Imagine that the government, with full support of 80% of all US citizens, banned doing business with anyone of Iranian descent, not just living in Iran. That's not feasible in the current climate, but it's certainly possible. I think I'd prefer it if such laws were fundamentally unenforceable.

But if the citizenry, like you said, doesn't care, how can it be a force that the citizenry desires to project?

They don't care to stop it. Status quo wins.

So if country A is at war with country B then the government of A shouldn't be allowed to prevent company C from selling items which materially benefit and provide aid and comfort to country B?