cellio | daf bit: Gittin 88

If a man refuses to give his wife a get then she is trapped in the marriage (even if he has left her) and cannot remarry. This is why the laws of gittin are so important -- as a protection for her. A mishna on today's daf tells us that we can go so far as to compel the man to give her a bill of divorce even under duress and the get is valid -- if under an Israelite court. If it is done under a heathen court, on the other hand, the get is invalid. However, the heathen court can flog the man and tell him "do what the Israelite authorities command", and if he writes a get it is valid. (88b)

So the compulsion can come from any court, but the instruction must come from an Israelite court -- we don't entrust gentile courts to rule on matters concerning Jewish law.

Note: This has been an issue from before the time of the mishna through to today. The mishna's view is not the final word on this nor the halacha, about which (I understand) there is some controversy. I'm just presenting what the talmud says here; don't draw broader conclusions from this.