Our military has about 10 times more funds than all contenders. We also try to keep a 10-20 year lead on competitors too. What we have as an advantage over most other countries is innovation. China may have the fastest super computer and more troops, but I guarantee ya the USA will win in any naval war(railguns are just one material science step away from being the sniper rifles to their shot gun boats), any aerial war(Russians newest jets where laughed at by mechanical/aerospace engineers because of how large and floppy they were), and I won't argue ground war because they got an advantage on their turf. Of course, none of this guarantees a win, but it is no exaggeration to say we hold a significant advantage. What other country can you say has Jets as advanced as ours, or will have rail gun mounted ships?