During 2005 war games a Swedish submarine 'sunk' an U.S. aircraft carrier, but in a real scenario, is that really possible? Isn't more probable that after releasing the torpedoes, the U.S. naval forces will immediately counter attack?

I don't know if you e ever played airsoft or paintball but in these games, typically, a hit is a kill no matter where it lands. If you get shot in the foot it's considered a kill and you must respawn.Naval war games (at least the ones I've been a part of) are much the same way.