Complex sentence: Stone also criticized Lenin and Trotsky for their "cruel and bloody ruthlessness" in deposing Tsarist autocracy in Russia; he scolded the U.S. Trotskyists for believing that Trotsky would have been less repressive than Stalin.
Split into simpler sentences: Stone also criticized Lenin and Trotsky for their "cruel and bloody ruthlessness" in deposing Tsarist autocracy in Russia. He scolded the U.S. Trotskyists for believing that Trotsky would have been less repressive than Stalin.