Complex sentence: In March 1921, he was sent to Germany to advise the Communist Party of Germany (KPD) and encouraged the KPD to follow the "Theory of the Offensive" as supported by Zinoviev and other Kunerists.
Split into simpler sentences: In March 1921, Kun was sent to Germany to advise the Communist Party of Germany (KPD). He encouraged the KPD to follow the "Theory of the Offensive" as supported by Zinoviev and other Kunerists.