As American operations against terrorism spread around the globe to places like Afghanistan and the Philippines, an increasing tendency has been for commentators to draw parallels with past experience in Vietnam. Even soldiers on the ground have begun to speak in such terms. The author analyzes the Army's response to that defeat in Southeast Asia and its long-term impact. Contrary to the accepted wisdom that nations which lose wars tend to learn best how to correct their mistakes, he argues that Americans tried to forget the unhappy experience with counterinsurgency by refocusing on conventional wars. While that process eventually produced the powerful force that won the Persian Gulf War, it left an Army with force structure, doctrine, and attitudes that are much less applicable to the peace operations and counterterrorism campaign it now faces. The author asserts that the Army must change in order to operate effectively in the full spectrum of future requirements, and it is time to reexamine the war in Vietnam. He also draws attention to the service's "Lessons Learned" process, and provides insights as to how the experience gained in Operation ENDURING FREEDOM should be analyzed and applied.