Sentence:  During the next five years liberal leaders in the United States sank in the cumulative confusion attendant upon and manifested in a negative policy of Containment - and the bitterest irony - enforced and enforceable only by threat of a weapon that we felt the greatest distaste for but could <WSD>not</WSD> abandon : 
Meaning of the word marked with <WSD> tags:  negation of a word or group of words