Sentence:  A nation such as Switzerland could be neutralized by agreement and could be relied upon to protect its neutrality ; more doubtful , but possible , ( with an assist from the North ) <WSD>was</WSD> the neutralization of the Latin American countries ; out of the question was the neutralization of Asia and Africa . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)