1) Doctrine 2) Irridentism 3) Philosophical system 4) Philosophy 5) School of thought 1) Irridentism 
Irredentism (from Italian irredento, `unredeemed`) is any position of a state advocating annexation of territories administered by another state on the grounds of common ethnicity or prior historical possession, actual or alleged. It is often advocated by pan-nationalist movements and has been a feature of identity politics, cultural and politic.....
advocating restoration of territory to a nation
[n] - the doctrine that irredenta should be controlled by the country to which they are ethnically or historically related
irridentism noun the doctrine that irredenta should be controlled by the country to which they are ethnically or historically related