You Never Know
Look at the world today, and think how unpredictable so much of it has been. Even a few months ago, nobody was predicting the events in Egypt. Three years ago, nobody could imagine what has happened in Syria. And during the battle there, the deep thinkers have swung back and forth on "who's going to win?" The truth is that we don't know, and we cannot know, since a lot of what happens is the result of chance, or irrational passions, or unexpected natural events. Have you read The Black Swan? Its subtitle is "the impact of the highly improbable."
This is intended to be a therapeutic blog post. Embrace skepticism, don't be so sure. Most of the time we're going to get it wrong, and we should expect that. Avoid the pundits, they don't have a very good track record, and they're generally reluctant to recognize error, let alone rethink the mental traps into which they fell en route to their latest blunder.
Remember there's a reason why the Wall Street Journal editors throw darts at the stock page. The stocks they hit generally do as well as, or better than, those selected by the highest-paid financial advisers.
The world of tomorrow is being shaped by human decisions, not by vast impersonal forces, and those humans don't know what they are going to decide. How can we? If you're making policy, it's best to reason from first principles, both moral and technical, and to watch for the first sign that you've got it wrong. When you spot it, change the policy as fast as you can, and keep it up until you find something that seems to work.
Every now and then you'll have an easy call, like fighting evils like fascism or communism. Even there, you may have noticed, policy makers have often had a very tough time getting it right and fighting evil.
Then console yourself with thoughts like Churchill's on America: Americans invariably do the right thing, after exhausting the other alternatives.