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human
CMV: World War 2 actually started in 1937

Many historians believe that World War 2 started when Nazi Germany invaded Poland but in my opinion, that's not when the war started. The precursor to World War 2 started in 1853 when the United States and other Western powers forced Japan out of isolation and invoked unequal treaties. Japan's economy took a hit and Japan desired to be more like Britain, France, Germany, Portugal, and Russia. In 1894 (First Sino-Japanese War), Japan fought a war with the Qing Dynasty to gain a sphere of influence over Korea and won. Later, they tried to take over land in mainland China and western powers did not approve of Japan taking over mainland China at the time. 

To me, Japan's desire to invade China in the 1930s was part of Japan's plan to become a colonial superpower just like Britain, France, and Spain. They wanted the western powers to view them as an equal and during the formation of the Treaty of Versailles, the western powers didn't held the same view. In my view, World War 2 started during the Marco Polo Bridge incident when the Japanese and Chinese armies clashed. The reason this is the case is because this conflict led to a massive conflict that impacted not only China but also the United States (colonizer of the Philippines at the time) and Great Britain (colonizer of Hong Kong and Papua New Guinea). The reason historians don't view the Marco Polo Bridge incident as the start of World War 2 is because world history has usually been Eurocentric at its core. In my AP World History class in 2011, most of what I learned revolved around the European powers with some references of North African, Southwest Asian, South Asian, and East Asian civilizations.

According to Wikipedia WW2 ended when Japan surrendered but started when Germany invaded Poland. This doesn't make sense logically. If Japan's incident with China didn't warrant the official start of WW2, then why did WW2 ended when Japan surrendered? Yes, it's true Japan didn't join the Axis powers until 1940, but Japan still played a major role in WW2.

Now, I know that my explanation isn't the best, but please try to counter or refute my view using strong arguments and evidence. Thank you.
gpt
World war 2 started when it was decleared.

You are describing leading up incidents. Ww1 didn’t start with franz ferdinands assassination, it didn’t start with britian building their navy, it didn’t start with britians industrious age. Those are all leading events. 

But once something has started, you can’t go back. Do you believe that the allies would have decleared war if germany hadn’t invaded poland? 

We are talking about the pinical action that directly started the war, otherwise we could go “a butterfly wing in paris started a war”.