Oh, I agree, the only solution would have begun for USN 18 months to 2 years prior, when Hart took command. 1st. Mac Arthur never gets any power over the Navy. 2nd. It would have required the establishment of a Naval Air station at Sangley Point, Olopongo, or at Miraviles. with a carrier size air group, a Spring 1941 withdrawl from China and strengthening of 4th Marines and the 2 independent Marine Battalions converted to Defense Battalions and the Radar unit kept out of MacArthur's control. 3rd. A miracle occurs and Hart finds a way to test his subs torpedoes, and discovers any one of the MK XIV issues, most likely the depth control or firing pin issue. 4th. the early completion of the ammunition bunkers at Miravales, and the torpedoes moved there prior to 10 December 1941.Hi Butchpfd, I'm unaware there were many agreements between the US and Britain regarding working together in the Far East. Previous conferences in this theatre had seen an America that was decidedly dragging its feet with regard to any military co-operation with the British or the Dutch. We have the exchange of liaison officers, and they did agree on lines of demarcation for military operations, sharing information from maritime air patrols, submarine operating areas, and more secretly, working together to crack Japanese codes. But the best Admiral Hart could do, until just before war broke out, was an agreement with the Dutch, allowing him to shift his surface fleet south into Dutch East Indies waters, away from certain destruction. There is this complete disjointed approach to defending the Philippines between him, being very realistic about his forces chances of survival, and MacArthur's view on what to do.
Any change to this historical line would be a major point of diversion, which is outside my remit, and to be honest, I find it hard to think of an alternative for the USA in this situation, without major changes to policy a good 12 months earlier, to give them any hope of doing better than they did. I think defending the Philippines is a more hopeless case than Malaya!
If the torpedoes at Cavite had survived, the S Boats and their functional torpedoes could have had some effect, with the torpedoes destroyed the S boats had to withdraw South after their 1st patrols, leaving about half the necessary torpedoes for the Fleet Boats on the Canopus. Once those were fired, the the Fleet boats had to move South too.
From what I have found, the destroyer agreement only went into place, when it was found how few destroyers would be accompanying Force Z, and the force was already enroute from Ceylon.