Sentence:  In a sense , the showdown promised by Mr. Hammarskjold 's sudden and tragic death has been avoided ; no precedents have been set as yet ; structurally , the <WSD>U.N.</WSD> is still fluid , vulnerable to the pressures that its new and enlarged membership are bringing to bear upon it . 
Meaning of the word marked with <WSD> tags:  any number of entities (members) considered as a unit