Two historical schools of thought have emerged regarding the origins of The Final Solution. In 1982, Tim Mason created the intentionalist vs. functionalist debate. The intentionalists argue that it was Hitler's intention from the beginning to annihilate and exterminate the Jews.
Neo-Gramscianism is a critical approach to IR and IPE which began with Robert W. Cox, a university professor at York University. The theory heavily relies on the writings of Antonio Gramsci. Here is a list of 10 theorists who contributed to field, including Cox. Check their work out, especially if you are doing research on the subject.