During World War 2, I know that many major companies helped out the axis powers during wartime. But did any of them get into any trouble after the war? For example BMW and Mitsubishi made planes for Germany and Japan respectively, and IBM assisted Germany with the help of their database system. But what were the repercussions for assisting the axis powers if you were an international company like IBM or Coca-Cola? And what were the repercussions for giving assistance if you were a domestic company like Mercedes or Mitsubishi?
IBM's assistance was overstated. They sold machines before the war and the new sensationalist book claiming they helped in the Holocaust is exactly that - sensationalism.
The world was in fact already highly internationalized back then in terms of business, to the point that the leading German truck manufacturer - Opel - was in fact a subsidiary of General Motors; who built tens of thousands of tanks for the Allies.
Hence in practice no action was taken because it's dumb back then as it is now to to blame companies for trying to sell goods to Germany or for owning German companies; especially since most of those transactions dated to before the outbreak of the war. That's all just part of regular business.
As for the companies within Germany and Japan themselves most underwent some restructuring but few actually went under and most exist in some form or another to this day. Mitsubishi is still one of the leading Japanese zaibatsu for instance.
In what is swedish is called the "Boschaffären" the Wallenberg brothers was punished for helping the Bosch company during the war. To avoid confiscation of Bosch daughter (?) companies the Wallenberg bought them, and at the same time made an agreement with Bosch that they should be able to buy them back after the war. When this agreement was discovered after the war, the brothers had their property in america confiscated. To understand the magnitude of these events one must know that the Wallenberg brothers were the most influencial business men that has ever existed in Sweden, and their influence over this country was probably the largest any business man has ever had in a single country. Together with the socialdemocratic party they were corporativism.
Jacob Wallenberg was the brother who was damaged the most by this incident, and never really regained his standing after it. Somewhat interesting is that he was the middle man between the Valkyria-group and Winston Churchill during the war. They were also uncles of Raoul Wallenberg, who is remembered for his struggle to help jews during WWII.
Source: Wallenberg. Ett familjeimperium by Gunnar Wetterberg