The Treaty of Versailles caused long-term instability in Europe (and parts of Asia) by ignoring the nations who had lost WWI. The treaty didn't provide any support for the nations who had lost, creating resentment in the hearts' of their people. This disunity allowed for the rise of facist dictators post-WWI, eventually causing World War II.
It was a bad decision on his part. Some may say his decision was good at the beginning but ultimately he made the choice to stay at war which led to a bad turn of events. Millions of dollars were spent on this and it wasn't even really successful, so I believe that was a poor decision.
The correct answer is C.Alexis de Tocqueville.
