"Wars then are prevented only by a balance of power and military deterrence..."
That perspective is known as the 'realist' perspective in international relations, and many of the more well know state actors of the twentieth century were realists in their foreign policy thinking. Both Hitler AND Nevile Chamberlain were realists. Chamberlain was a staunch supporter of British involvement in WWI and was one of the loudest voices for re-armament in England in the 30s to counter fascism.
When he abandoned this perspective, opting instead for the 'social constructivist' perspective by appeasing Hitler to prevent WWII, he instead made the conflict inevitable.