That does not justify overthrowing another country's government. Most countries, including the United States, recognize the state's eminent domain over its land and its natural resources. Besides which, the Iranians tried to negotiate, the British refused, so the Iranians nationalized in response.

A foreign coup is a valid response to nationalisation?

I'm not sure. But nationalisation is certainly a violation of rights.

Of course, I'd be interested to see how those assets were set up in the first place - my bet would be during a non-rights-respecting period of colonialism.

How far back do you go? (Serious question).

You go to when the country got a democratically elected government.

As for nationalisation is certainly a violation of rights do you hold that all eminent domain is a violation of rights? IE if the government wants to build a road and uses compulsory purchase orders it's a violation of rights?

Yes. It's possible to do such things in non rights violating ways. For example, buying options on properties and exercising them when a route is made.