The US military is an instrument which gives its wielders unparalleled power, and it won't have any plausible rivals for the foreseeable future. While it more or less failed in its nation building missions in Iraq and (one imagines) Afghanistan, it seems to me this isn't a blight on its reputation since copying/pasting institutions that took centuries to develop in the West into less developed regions in the span of a decade is an impossible task period, let alone an impossible task for a military.