My first thought is that it would take considerable time to expand the Navy personnel from its current max of
- 33,380 Regular
- 4,000 Maritime Reserve
- 7,960 Royal Fleet Reserve
This includes 8000 plus Royal Marines
To the what 90 odd thousand in 1965ish?
In 1960 total military GDP is 6.76% and 441 ships (excluding Minesweepers)
In 1970 total military GDP is 5.42% and 184 ships (excluding Minesweepers)
Today total military its about 2.3% and 50 odd ships (excluding Minesweepers)
(Why you would want to exclude minesweepers given they are the best crewed ships is beyond me?)
So.....
Wages and Pension for another lets call it another 55,000 personnel, plus the housing, supporting civil servants family stuff etc - is going to be staggeringly expensive IMO far beyond 6.72% of 1960
And then you have to build the ships....about another 100 plus including RFA ships at least
I'm calling it - 10% of GDP (about 8% more of todays budget)
There would have to be a major threat to Britain for the British people to stomach that - and if there was such a threat then the Army and RAF would also be expanded and well....now we are 15 - 20% of GDP and probably, no, almost certainly reintroducing conscription.