From security expert Bruce Schneier:
As Americans, and as citizens of the world, we need to think of ourselves as security consumers. Just as a smart consumer looks for the best value for his dollar, we need to do the same. Many of the countermeasures being proposed and implemented cost billions. Others cost in other ways: convenience, privacy, civil liberties, fundamental freedoms, greater danger of other threats. As consumers, we need to get the most security we can for what we spend.
The invasion of Iraq, for example, is presented as an important move for national security. It may be true, but it’s only half of the argument. Invading Iraq has cost the United States enormously. The monetary bill is more than $100 billion, and the cost is still rising. The cost in American lives is more than 600, and the number is still rising. The cost in world opinion is considerable. There’s a question that needs to be addressed: “Was this the best way to spend all of that? As security consumers, did we get the most security we could have for that $100 billion, those lives, and those other things?”
If it was, then we did the right thing. But if it wasn’t, then we made a mistake. Even though a free Iraq is a good thing in the abstract, we would have been smarter spending our money, and lives and good will, in the world elsewhere.