International relations exists in a state of anarchy. In practical terms, this means that

a. nation-states do not have allies or principles, but instead only interests. 
b. only the United Nations has the power to resolve disputes between nation-states. 
c. there is no sovereign authority that resolve disputes or enforce international law. 
d. foreign relations is marked by unending conflict and war. 

c. there is no sovereign authority that resolve disputes or enforce international law.