Technically, not true. The US has created absolute supremacy (for now) in traditional warfare, which means a good degree of supremacy in national politics.
What we're seeing now is the emergence of a non-traditional form of warfare, used by weaker parties since they can't hope for a fair fight on the battlefield. In other words, a near-total reliance on surprise-attacking civilian targets, i.e. terrorism, a field in which small, underfunded groups of more or less competent people can utterly smash a huge, wealthy, but unwieldy government organization. It's been implemented broadly, with (arguably) great success in Israel by the Palestinian refugees, and the concept of such strikes as a legitimate option to traditional war is reportedly spreading like all get-out.
War ain't for the Army any more, and battlegrounds aren't restricted to the more poorly defended country. Get used to it, we'll be seeing a LOT more of it in the years to come.