According to Bruce Schneier's blog entry, "It isn't hard to parody worst-case thinking, and at its extreme it's a psychological condition.". Case in point: http://xkcd.com/748/

Thinking about risk is hard to do correctly, as Mr. Schneier has stated numerous times. We try to do it all the time, and if you're the U.S. government, we usually fail miserably. The excitement of considering extreme but improbable risks can be intoxicating and even addictive to some. But it can lead us on a never-ending spiral that brings us no closer to the answer of how best to allocate resources to reasonably mitigate risk / expected loss. Sadly, what usually follows are poor outcomes and bad decisions.

I propose that we eliminate the phrase "worst case scenario" from our vocabularies (OK, just decommission it - it's cheaper) and substitute "bad enough situations". What I mean is that improbable, unexpected events will happen. Unforseen consequences will materialize out of nowhere, and dynamic impacts will cascade like dominos. And they will be "bad enough" to be called or perceived as disasters. But the key is to use this information in a positive way.

In the context of disaster planning and preparedness, "bad enough" thinking helps us shift our focus from particular disaster scenarios and their likelihood to the dependencies that support our activities or operations. "Bad enough" tells us how long we can be without these dependencies, and then moves us to figuring out and testing work-arounds. In my opinion this should result in a "good enough" plan, the Holy Grail of disaster planning. I've heard various EMA and health officials refer to taking an "all hazards approach" when preparing for disasters. Seems quite reasonable to me.

"Bad enough" thinking is a much less depressing and exhausting exercise than flexing our worst-case imaginations. Besides, the only real benefit of worst-case thinking is that it can be used as empathy - "You think it's bad now? Well, it could be worse!"