Answer:
World War II
Step-by-step explanation:
Half of the world fighting against each other and millions were dying. That isn't exactly the best possible scenario for globalized economic integration.
The great depression started on October, 1929, and it lasted for almost a decade, until World War II started in 1939. The allied nations were at war with the axis nations, the US was officially neutral, but it wouldn't trade with axis nations. All of continental Europa was dominated by Germany and its allies (axis nations) and most of the Asian pacific nations were dominated by Japan (also an axis nation), so the possibility of trade integration was very limited.