In April 1920 Lenin would complete writing "The Infantile Disease of "Leftism" in Communism", a guide to the final stages of the Revolution. He became overconfident, entertaining the thoughts of a serious war with Poland. According to him and his adherents, the Revolution in Russia was doomed unless it was to become worldwide. The debate in Russia was "not as to whether the Polish bridge should be crossed, but how and when." According to Lenin's doctrine of "revolution from outside" Red Army's advance into Poland would be an opportunity "to probe Europe with the bayonets of the Red Army", the first attempt to export the Bolshevik Revolution by any means necessary. In a telegram, Lenin wrote: "We must direct all our attention to preparing and strengthening the Western Front. A new slogan must be announced: Prepare for war against Poland."