I would say Liberalism, in my opinion.
Former US President Harry Truman is known for the foreign policies he implemented in response to the growing tension between the United States and the Soviet Union. Among his foreign policies is the Truman Doctrine wherein it is usually offensive in nature because it aims to fund a territory when it is under retaliation from a communist rule.
People believe that the war lasted four years .
I'm guessing you are talking about the Eastern Roman Empire, or the Byzantine Empire.
the Byzantine Empire a) remained strong for several centuries, until it fail to the Ottoman Turks at ~1346 ad
hope this helps