Maybe they'll start talking about it again if the Iranians manage to sink a Nimitz. Peak oil is not an energy crisis. It is a liquid fuel crisis.
However, they are blatantly about heading toward a hostile coast under fire, able, in the classic Battleship combat mission, to take fire and keep on going.
The biggest platform where I can see a plausible argument in terms of keeping sea lanes open against piracy and other forms of unruly behavior on the high seas is the Cruiser sized light aircraft carrier, like the Invincible and Illustrious.
Of course, Sarkozy's proposed European naval unit would form a battle group around one of the British light carriers, reportedly because the Charles De Gaulle is in dry dock for repairs. So saying that is the largest platform were a plausible role could be advanced is not the same as saying that no mischief could be done with the platform. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.