Complex sentence: Anti-Japanese sentiment traces back to World War II and the aftermath of the war, where an estimated one million Filipinos, of a wartime population of 17 million, were killed during the war, and many more injured.
Split into simpler sentences: Anti-Japanese sentiment traces back to World War II, and the aftermath of the war. Where an estimated one million Filipinos, of a wartime population of 17 million, were killed during the war, and many more injured.