OK, if we're off on thar conversation then you need to understand the NATO rules.
1. Take arms against one member you take arms against them all.
2. The UK would never deploy strategic nuclear weapons without US agreement.
3. If the UK were to be picked on individually for a nuclear strike, the US would retaliate. Ditto Germany, Benelux, Spain, Scandinavia Poland and any other NATO country.
4. Potential enemies know this.
So, how would our money be better spent? I say, by providing a well equipped, well manned, highly technological conventional UK defence force and a highly skilled, specialist attack and response force as part of NATO. I am sure that would suit America and our European allies. Our nuclear force is only maintained in order to retain a place at the top table. And a bloody expensive boast it is too!