It always comes as a great shock to journalists and the little intellectuals twits that infest Washington when they discover that the U.S. Armed Forces are actually comptetent. It just goes against everything that they have been taught by their leftie professors and heard from their policy wonk friends.
The Army and the Marine Corps are quite good at counterinsurgency when they need to be. In Vietnam, the insurgents had their Waterloo in Tet 1968 and thereafter the war was one of conventional forces fighting in a jungle environment. The North Vietnamese Army, with tanks, defeated the South Vietnamese Army some two years after the U.S. Armed Forces sailed away.
While its quite true that many of the lessons learned from our counterinsurgency experience had to be relearned, we were quite right to focus on the real threat to Freedom - the Soviet Empire. We would not have defeated the Soviets by focusing on the Blue Helmet thing, we needed to demonstrate that the Russian Bear could not prevail. We did, and the Empire collapsed.
The Officer Corps has moved seamlessly between the academic world and a full load of battle rattle for years. But, unlike Brooks and others of his ilk, they have recognized the nonsense coming from leftist academics for what it is.
But we broke a hell of a lot of their tanks -- B-52's caught them on open roads in 1972 and junked them right there -- and killed a million of their most dedicated cadre.
The little bastards never got to Singapore.