We could never have a picture of the way on which the world revolution will come (picture necessary even when history disappoints the favourable odds, and without which the Marxist party cannot exist), without wondering why there's no revolutionary class struggle between capitalists and proletarians in America, right where industrialism is more powerful. The answer cannot be separated from the consideration of the U. S. success in all their imperialistic enterprises directed to the exploitation of the rest of the world. The power systems in America and in England aim exclusively at the conservation of the world capitalism: being prepared for this task by a historical forceful movement in the same direction, they proceed with measured steps towards a social and political totalitarianism, inevitable preamble to the final antagonistic clash. Obviously, the world will fall into crisis only contemporarily with the collapse of the formidable capitalistic system centred in Washington, which controls the five sixths of the economy ripe for socialism, and of the territories with pure wage-earning proletariat. Revolution will necessarily have to pass through a civil conflict in the United States, which an American victory in a new world war would extend for a period measurable in half-centuries (Raddrizzare le gambe ai cani *, 1952)

*(lit.) to straighten dog's legs; (fig.) to attempt the impossible

the article is right here----> http://www.quinterna.org/lingue/english/articles_en/turning_point.htm