1) Doctrine 2) Philosophical system 3) Philosophy 4) School of thought 
In general, expansionism consists of expansionist policies of governments and states. While some have linked the term to promoting economic growth (in contrast to no growth / sustainable policies), more commonly expansionism refers to the doctrine of a state expanding its territorial base (or economic influence) usually, though not necessarily, by...
(from the article `intelligence`) ...in a proliferation of new intelligence agencies in the 1920s and `30s, particularly in totalitarian states (Italy, Germany, and the Soviet Union) ...
[n] - the doctrine of expanding the territory or the economic influence of a country
noun the doctrine of expanding the territory or the economic influence of a country
a policy of expansion, as of territory or currency: the colonial expansionism of Europe in the 19th century.