In the throes of the debate over the war in Iraq, I found myself drawn to the Reagan Library in Simi Valley, CA. Behind the entrance hall stands a slab of the Berlin Wall. After taking in the museum twice, and securing Nancy Reagan as a point of contact with the Reactionary Right, I took my boys to the museum to see the slab.

On the way, I explained the nature of the Vietnam conflict: how the American people were lied to about the events that triggered our entry into the conflict; that we were proxies for a unmotivated native army; and that we fought the conflict without a clear idea of where the peace would take us. For those failures, we were led into a domestic political abyss that greatly damaged our nation, and whose aftereffects still reverberate today.

Standing in front of the wall, I asked my sons what kind of symbols they saw there. The slab was dominated by a flower and a butterfly painted in pastel colors. After pointing out that these were symbols of peace, rather than of martial aggression, I observed that Ronald Reagan executed the final steps of a policy that overcame Russian tyranny in Eastern Europe. It was a policy that sought to deny resources to the aggressors, whose tyranny denied them the full energies of the people they led. Unable to marshal the energy to compete with us, their ability to maintain control collapsed.

The Cold War is not the only example of the successful application of defensive engagement. South Africa must also ranks high among them. Our policies in Taiwan, Japan and Israel are also examples.

The greatest successes of the modern struggle against tyranny focused first and foremost on achieving a sustainable peace. The policies of peace through defensive strength are the purest applications of that process. When that fails, as it did in Kosovo and Rwanda, a merciless and timely application of force is required.