Sentence:  Russian tanks and planes in Cuba jeopardize the security of the <WSD>United</WSD> States , violate the Monroe Doctrine , and threaten the security of every other Latin American republic . 
Meaning of the word marked with <WSD> tags:  North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776