The Pacific War. Regarded as a backwards region fit only for exploitation by Western nations, the fledgling Empire of Japan shook that perception to the ground in late 1941 by tearing into the Asian imperial holdings of France, the Netherlands, the United Kingdom and the United States. Four years of warfare defined by viciousness and brutality followed, with fighting stretching from India to shores of Alaska as the old empires struggled to contain and push back their new Asian competitor.