Marx had correspondence with the early partisans in Russia. He warned them that they were doomed to failure, and that he wouldn't support their cause. Apparently, he eventually gave them approval, but in a kind of reserved way. Lenin would have been keenly aware of this, but I suppose he decided that either he was smart enough to figure it out, or his ego was such that he really only desired the personality cult. Probably both. Whatever the case, the failure of Russia in WWI was the perfect opportunity to seize control, and it was actually Germany who was responsible for transporting Lenin from Switzerland, where he lived in exile, back to Russia. To them, it was a type of alternative warfare to bring down the czar from within. It's a great lesson in figuring out if the sure is worse than the disease before implementing it.