Sentence:  `` As long as Mr. Khrushchev <WSD>is</WSD> convinced that the balance of world power is shifting his way , no amount of either smiles or toughness , neither Camp David talks nor kitchen debates , can compel him to enter fruitful negotiations '' . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)