the truth is that those parties and leaders are opportunists and traitors to the working class that are unable or unwilling (do not say, "i can't"; say, "i shan't") to use illegal methods of struggle in conditions such as those which prevailed, for example, during the imperialist war of 191418, when the bourgeoisie of the freest democratic countries most brazenly and brutally deceived the workers, and smothered the truth about the predatory character of the war.

How would the previous sentence be correctly capitalized?
The truth is that those parties and leaders are opportunists and traitors to the working class that are unable or unwilling (do not say, "I can't"; say, "I shan't") to use illegal methods of struggle in conditions such as those which prevailed, for example, during the imperialist war of 191418, when the bourgeoisie of the freest democratic countries most brazenly and brutally deceived the workers, and smothered the truth about the predatory character of the war.