It was my understanding that in PSTN at country-level boundaries the operators choose to forward calls, and do billing and such recording: at that point they decide whether to put the call to the local country network or not. If the call has meta-data as if its come from the local country then they could drop the call request, but they establish the voice call [because call senders pay more than call receivers, presumably].

Is that incorrect?

https://en.m.wikipedia.org/wiki/Signalling_System_No._7