Sentence:  Essentially this imposed two conditions : First , international law had to recognize and be compatible with an international political system in which a number of states were competitive , suspicious , and opportunistic in their political alignments with one another ; second , it had to be compatible with the <WSD>value</WSD> system that they shared . 
Meaning of the word marked with <WSD> tags:  the principles of right and wrong that are accepted by an individual or a social group