BACK in the 1950s and early 1960s, when the fledgling South Vietnamese army was largely relegated to the task of guarding roads and villages, American "advisers" not only taught their inexperienced charges but frequently led them into combat as well on the rare occasions that ARVN was allowed to "liberate" a Viet Cong hamlet. Nowadays advisers barely even advise. In fact, says Major Jerry G. Williamson, a veteran of three tours in Viet Nam, "these guys don't really need advising. We're mostly out here to talk to FAC [forward air control] pilots and coordinate air strikes."
On instructions from Washington, the...