Complex sentence: Although the Communist Party had worked hard to warn Canadians about the growing fascist danger, after some debate the Party saw the opening of World War II not as an anti-fascist war but a battle between capitalist nations.
Split into simpler sentences: Although the Communist Party had worked hard to warn Canadians about what it considered to be a growing fascist danger. After some debate the Party saw the opening of World War II not as an anti-fascist war but a battle between capitalist nations.