Global revolution to me happening seems too far fetched. It makes more sense that socialism could be established in one powerful country, a country which would then work towards spreading the ideology and helping support revolution world-wide. Especially in other significant world powers. And then after workers were liberated globally, communism would be possible. But for now the main goal should be socialism. You have to walk before you can run.
As Lenin said:
Complete and final victory on a world scale cannot be achieved in Russia alone; it can be achieved only when the proletariat is victorious in at least all the advanced countries, or, at all events, in some of the largest of the advanced countries. Only then shall we be able to say with absolute confidence that the cause of the proletariat has triumphed, that our first objective—the overthrow of capitalism—has been achieved.