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 ) was the <WSD>neutralization</WSD> of the Latin American countries ; out of the question was the neutralization of Asia and Africa . 
Meaning of the word marked with <WSD> tags:  action intended to keep a country politically neutral or exclude it from a possible war