The US did not go through a long period of active direct and proxy conflict with the most advanced contemporary nations at it's founding. It fought a brief war to separate (which it was losing until a major power opposed to Britain intervened), and then not much with any major power till it decided to take advantage of the Napoleonic Wars and the pretext of impressment to seize British Canada (unsuccessfully). The US was a sideshow isolated by oceans for the major powers for almost as long after it's formation as the USSR existed.
