Most of the time, when we read and hear about security we are talking about traditional, national security conceptions of security. In the traditional conception of security, the greatest danger to a country is from military threats. The source of this danger is another country that by threatening military action endangers the core values of sovereignty, independence, and territorial integrity. 

What is the security policy of a country which aims at limiting or ending war called?

Defense

Therefore, security policy is concerned with preventing war, which is called deterrence, and with limiting or ending the war, which is called defense.