keesje, I would have thought 4.7% is a very low percentage. I wonder where the biggest shares of the spending is going!
I think the US will decline in a big way, right now they are by far the most powerful nation on Earth and I think will stay that way for a while. But give it maybe 20 years, possibly less and I can see a China that is stronger. The trouble for the USA is that they cannot afford to keep the military at its current size, the Chinese however can afford to expand, so as one side shrinks the other will grow. Maybe they will pass each other along the way! Even after this though unless the US falls apart they will still be a major power, they may not be the strongest but I don't think many would wish to take them on. On the other hand they will have to accept no longer being number one.
India to will be important but not in my opinion as strong as China. Russia will be very powerful to, with so many resources and her military power she should be able to dominate Europe fairly well, I think Russia will be a major global power again, more important than she is now, probably in the top two or three.
Europe is the continent which will be totally out of it, in economic decline and in military terms only a paper tiger, no match for Russia or China even now.