Atlas's parallels are perfectly correct. But his history is badly truncated, which leads him to fundamentally misunderstand the dynamics.
The key point is that the "original" neoconservatives were themselves a reprise of the debate that founded the cold war, between cold-war liberals and Wallacites. The reason the first neocons emerged in the wake of the Vietnam war is precisely because that war called the cold war consensus into question. They fought to rededicate the country to the anti-communist crusade. And they succeeded. The newest debate is the third time we are fighting the same battle again: whether the international arena should be divided into Liberal Society and its Enemies -- or whether the goal of international affairs should be greater cooperation, toleration and peace, and the amelioration of our opponents through soft power and development. Whether we should rededicate ourselves to another 50 year cold war, because cold wars are good things that keep our values strong and make the world free; or whether we should rejoice that we are finally free from that vast waste of human lives and resources and do everything we can from getting trapped in it again and the tyrannies it made possible.
So for both the original neocons and the newest crop, defense of a particular war and attacks on its opponents was never the nub of the argument. The attacks are so fevered precisely because both wars represented something larger. In both cases the debate was consciously experienced as a fight between defenders and critics of an enemy-based worldview and over its future.
Both the Vietnam and the Iraq War brought this clash of worldviews into focus and into question. And then, simply by being wars, they supercharged it. Wars force people to choose sides. They remove the middle ground, and make life and death and freedom and slavery the stakes of people's opinions. This is why support for these wars became the touchstone of allegiance to different sets of values, and why both sides regarded the other as a danger to the country and the world. The wars were not regarded as epochal in themselves, but rather, and rightly, as possible turning points in world history -- when one world view might possibly be supplanted by another that might last for a quarter or a half a century.
This debate has always divided the broad liberal left into anti-war left-liberals and pro-war anti-stalinist neocons since its very beginning right after FDR's death. At the bottom of it are two incompatible conceptions of liberal society -- Liberal Society as necessary based on a mobilization against its Enemies; and Liberal Society as fundamentally based on tolerance. For each side, the other represents the death of Liberal Society. For enemy-based liberals, lack of defense of our values will lead us to dissolve from within into relativism. It will paralyze our will, and make us helpless prey to fanatics who are certain of themselves while we are consumed with dilatory self doubt. And for tolerance-based liberals, intolerance is what will corrode liberal society from within and make the world without into an endless battlefield.
Michael