I would think that a fifth or sixth submarine would be needed.
As for the debate, I actually thik that moral and international relations have to be dissociated. As a country, there is a need to force oneself to follow rules, but at the same time acting as if the others would not be following said rules. This ensures the general following of rules by everybody.
I rather regret that Britain and France are still unable to cooperate in missile subs matters, as this would cut costs tremendously and improve credibility. Arguments on the cost do not hold if costs were divided between Fr and Gb or better even, divided between all UE members.
The main problem for such a cooperation is the necessary unicity of command for these weapons. A free fox in a free henhouse!
Otherwise I agree completely with your post. Peak oil is not an energy crisis. It is a liquid fuel crisis.
by building all six submarines one per year, you would earn a lot of money, say half a sub. A free fox in a free henhouse!