New world order: stability or rise and fall?

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Consider the following thought experiment.
Suppose we could be assured that there were going to be no major wars in the future. Small stuff maybe, but nothing like WWII where the major powers go after each other tooth and nail.

Now in that environment which of the following is most likely:
A. The nations of the world would trend toward comparable levels of economic well being.
B. Various nations would "rise and fall" in the sense that some would have more economic success than others, but the arrangement at any one time could not be expected to continue indefinitely. A country's rise would be economic not military.