The original premise of the thread appears to have been forgotten.
Would retaining the Anglo-Japanese alliance have meant no Pacific War?
Unless someone can explain why Great Britain would forfeit ties to the US and most of the British Commonwealth in return for a treacherous and minor ally from WWI the answer would have to be negative.
Minor because Japan's support during WWI was indeed minor, consisting largely of seizing what was assigned to Japan, certainly paling in comparison to either the Canadian or Australian efforts during the war.
Treacherous because Japan was constantly in touch with Germany, ready to betray the alliance if it seemed likely to be profitable and always willing to try and extort more out of the Entente in the interim.
Amusingly the Germans never realized the significance of their secret proposals to Japan somehow always being public knowledge in short order.