Unfortunately for MAD, which has worked up until now, there is one slight flaw when it comes to Iran et al. That is: they're mad. Stark raving mad. We are now moving from conventional warfare to a new kind of warfare in all aspects including political warfare. But as I said, it sure is worth keeping that insurance policy.
Let's look at it like this. UK loses its deterrent. Iran creates its own. Iran improves it to a standard where they can strike the UK. Who now holds all the cards? Iran: you have one week to leave all Muslim countries, UK, or we nuke you. What choice do we have then? Iran (or whoever) would then hold more political and physical might than the UK.
As for the RAF/Navy holding the all the toys debate, my personal views aside, a decision was made a number of years ago, whether it be from a beancounter perspective or 'lets have the most effective deterrent we can' perspective (ha) and that decision is unlikely to have changed in recent years as the purse strings get tighter and tighter and the deterrent becomes less relevant and less justifiable to Joe Public post-Cold War.
Easiest decision for TB? Politically and Economically: keep the deterrent. Keep it with the Navy.
Original thoughts: maybe a surface based ship launched missile? They are all floating about anyway and are capable of firing cruise missiles. Why not change a couple of warheads around? Maybe an easy target on the surface though?
