In theory, yes, in practice, with our limited resources, I’d rather we had more surface ships, helicopters and soldiers. These are the things that would actually be used in the future. The nuclear deterrent is just a deterrent, and it only needs to be good enough to make a hostile nation fear the consequences of launching a WMD attack on Britain...
In the 2011 Fiscal Year the UK Central Government spent £512.2 billion. Only £35.4 billion of that went to the military. The major budget items are pensions, heath care and welfare. The is what drives the public debt.