Its popular to bash RN interwar leadership.
It was difficult for the RN to concentrate like the USN could for 'Fleet Problems'. Most tactical thought went into using carrier aviation to wing an opponent [Bismarck - Ya!], and then finish it off at night [Pola & friends - Si, Si, Si!]. Against the IJN it was County class CA and O,P and R class submarines (they wanted 30 Thames class Fleet Subs) to hold the line and harry the IJN till the battle fleet arrived.
This is a very good book on the subject:
Military Innovation in the Interwar Period
The problem is that there were not that many submarines in the late 20s through to the late 30s
Germany from 35 were allow 40% of the number of British subs which was about 50 - so 20 odd!
Italy had more but - they were not viewed as an enemy until the late 30s
The RN specifically went in to London with the aim of capping Japanese submarines which was successful, ie Japan wanted 90,000tons and accepted parity with the US and GB. The RN was confident it had mastered the submarine but the Submarine School at Portland had other ideas.
Unfortunately the 10 year holiday (that lasted for 20) pretty much retarded much in the way of development and few could have predicted how ww2 would turn out
The RN had already been in 5 years of holiday before Washington.
The USN pretty much was able to dust off its campaign plans for the Mandates but this also had to include some heavy land fighting on PNG and Guadalcanal (and the loss on Philippines) and not even the fleet problems predicted that the entire fight would be by aircraft for the major fleet actions or that the lesser multiple SAG actions would force them to exchange cruisers for IJN destroyers
The USN Fleet problems were more about tactical solutions, it was the table top gaming that worked on the strategic questions and this delivered on the far more important results like:
- We don't have enough cruisers - how about we initiate coalition war with navy's that have cruisers ie. British Empire. (to suggest this was truly career ending)
- It's too easy to cripple a carrier and its a long way to base - design carriers to be repaired in theatre.
- It will take 3 years to build a fleet and the US population will lose interest over that time - no answer.
Planning against Red was beneficial because it generated the list of Islands in the Caribbean that the US would want for bases and it only cost 50 overage destroyers in 1940. Bargain.
For the RN strategic planning, they planned against the US and they were smacked down by politicians. Then later the 'Locarno Wars' where they may need to fight France to support Germany and they were smacked down by politicians. Finally Japan occupied full focus and they were smacked down by politicians.
The RN did have tactical gaming rules that were too optimistic, River Plate should have been over in 30 minutes. US rules seemed to be more realistic in this respect.
Also, a major reason that asdic wasn't the cure was that uboats often operated on the surface by night (once they had sufficient numbers and until radar made this too dangerous). This probably wouldn't have been revealed by more extensive exercises before the war, it requires both a conceptual leap (they are submarines, why would they operate on the surface near surface warships) and large numbers of submarines and merchant ships for the advantages to be clear. Then, even if it was realized it's not clear what the appropriate response is until better radar is available
This is not to say that British ASW equipment and training was anywhere near as good as it could have been at the outbreak of war
The RN knew that in 1918, 2/3rds of submarine attacks were at night and when on the surface. They had also done the maths in WW1 that the larger the convoy the better but then forgot that and took till 1943 to work it out again.
Indeed USN submarine doctrine was very constrictive for the first year or so of the pacific war with submarines staying submerged all day and only surfacing at night meaning that they often did not see the enemy resulting in a very poor result from the early war patrols - so the pre war exercises did not help there!
Pre-war, US Sub commanders were
criticized in exercises if they were
detected/spotted. This led to overly cautious commanders that were eventually replaced.