Perhaps Michael Gerson is trying to be funny:

I’ll leave it to others to critique Bush’s choices on Iraq and other issues, a task considerably easier than making them under pressure [bold mine-DL].

I think almost everyone cuts political leaders a fair amount of slack in emergency situations and crises that seem to come out of the blue. How political leaders respond in those circumstances tells us something important about them, but there is also a basic desire on the part of most people in any country to want their leaders to be successful in responding to a sudden attack or to a natural disaster. Later on, there will be mostly reasonable criticism of the preparedness and personnel choices that the political leader made before the emergency happened, but the common instinct in the moment is to give the politician a chance to do what he was elected to do. Most people aren’t likely to tolerate bungling the management and preparation for a major war that the politician chose to start, and they’ll be even less forgiving when it turns out that there was no reason to fight the war in the first place. What separates the decision to invade Iraq from other decisions that Bush made was that it wasn’t being made in the midst of a crisis and it didn’t come in response to an Iraqi attack. Even if claims about weapons programs had been true, there was no need to invade Iraq. There was no pressure on Bush in this instance. There was a crisis atmosphere that the administration and its allies created in order to scare the public into supporting the war, but that’s something else all together. It was a policy that Bush pursued because he wanted to pursue it.