NonCredibleDiplomacy

Demanding other countries give land away is imperialist not isolationist. Like most authoritarians on the rise they use populism and claims of national focus ie. isolationism to lure people in then they soft walk in more and more imperialism generally after a false flag or suspicious incident that they use to gain unitary authority and never give it up.

I'm not huge into the prequels but if you actually pay attention to the boring government parts it is a fairly good example.