The only real policy threat we faced was assuring an adequate oil supply.
Since after all it is our right to invade nations and murder people to assure ourselves an oil supply?
As we become less powerful will it be OK for foreign nations to maintain standing armies in the Mississippi River and naval blockades along our coasts so as to ensure a steady flow of grains?
Or is the question silly because they have no power to do so and that's all that really matters.