Yes thing are different during a war. That sub would have fired a torpedo.
Remember in war there are two sides to every story.
We all hope that our side always wins, but unfortunately the other side hopes so too.
Anyone who underestimates the opposite side will lose. What makes anyone think that we are totally capable of protecting so large a target at all times?
Your optimism is great, but the other side is improving every day also.
By this logic a tank, costing 5 million dollars, is useless because a guy with a $2,000 shoulder fired missile can destroy it. I mean you people are ridiculous.