You cannot use anthropic principle here. Unless you postulate some really weird distribution of risks unlike any other distribution of anything in the universe (and by the outside view you cannot do that), then if risks were likely we would have many near misses - either barely getting away from total destruction of humanity, or events that caused widespread but not complete destruction. We have neither.

Global warming and Iraq war are tiny problems, vastly below any potential to threaten survival of civilization. Totalitarian regimes have very short half-lifes. Threat of the Cuban missile crisis seems vastly overstated, especially considering how many wars by proxy United Stated and Soviet Union fought without getting anywhere close to using nuclear weapons, and how nothing indicated intention of either party to resort to nuclear attack.

Communist Russia didn't went that badly by historical standards - standards of living when it ended were a lot higher than standard of living when it started, and if it shows anything is how remarkably resistant civilization is, restoring itself so smoothly after Stalin in such a hostile environment. You see the same pattern in China and so many other totalitarian regimes worldwide - how they get softer and more civilized given time, peace, and economic prosperity. We seem very well protected here.