(CNN)Think of the mistakes the United States has made when it has acted out of fear, convinced that its enemies were 10 feet tall and about to triumph. In the 1950s, it helped depose democratic leaders in the Third World, fearful that they would become socialists. Later, it intervened in Vietnam. It supported the apartheid regime in South Africa. It invaded Iraq.
The case for optimism
On the other hand, when we have kept threats in perspective and understood that time was on our side, we have patiently organized our allies, negotiated agreements with our adversaries, built our internal strength and, in the end, prevailed. It is not as satisfying as the imagined thrill of military victory, but it has been a much surer path to stability and success.