In other words, imagine a hypothetical world where the reaction to 9/11 was "damn, let's figure out who was behind this, go arrest them, and rebuild and carry on with our lives" rather than the "holy shit, let's declare a war on terrorism" reaction that actually happened. Do 430,000 jobs still get lost? No, I seriously doubt it. You lose some jobs because a bunch of office space got destroyed, but most of those jobs are still needed and will simply be relocated.