Militarily, what we really need is some strategic nuclear ability. So we have the ability to destroy Russia if they bother us. It will be enough as a deterrent so they won't. It's kept us all safe for 80 years. Russia for example has less resources than the bigger European countries and the only reason we worry about them is that they have nukes.

Part of the problem is that the US has always opposed us having our own nuclear deterrent. They've always opposed France and have hamstrung the UK's options. In return the US promised to take care of this for us but we can't count on that anymore so I totally support building this out.