Umm... We all saw it happen September 11, 2001? You're right that an attacker probably wouldn't back out just because the attack wouldn't be maximally effectiv

Umm... We all saw it happen September 11, 2001? You're right that an attacker probably wouldn't back out just because the attack wouldn't be maximally effective, but the result would still be reduced casualties. Ideally, you want to prevent all attacks, but even when you can't the next best thing is to reduce the severity.