Just watched an interesting doco on the campaign in North Africa during WWII and the extent the British went to in trying to get the US to engage in the war from 1940. What was particularly interesting is the access to every aspect of British Military operations granted to the US Military Attaché at the embassy in Cairo, in the hope of impressing the US and gaining further support. From this it is quite clear that the Roosevelt and the General staff were keen on entering the war irrespective of Japan.
The general staff apparently wanted to invade Europe and saw the Mediterranean as nothing but a distraction, but the Cairo Military Attaché, one Colonel Bonner Fellers was keen to get involved in North Africa and managed to get Roosevelt (who had personal access to Fellers extensive reports and opinions) on side. I am surprised I had never heard of Fellers before such was his impact on that entire theatre and quite possibly the way as a whole, especially having seen a second, more revealing doco and read further on him.
Fellers would send five or so highly detailed coded reports through the embassy to Washington each day, using the State Departments Code 11 (he apparently queried the security of this system but was ordered to use it). These reports contained British troop dispositions, strengths, equipment, plans, tactics, logistics as well as his observations (and probably quite biased opinions) on morale, quality of leadership and standard of equipment as well. He was apparently thought by others in the US army to be an Anglophobe, with his reports highly critical of the British Army and its continual failures in the Western Desert. He was also apparently intensely disliked by Eisenhower and many other senior officers (Macarthur being the exception).
The irony is the Italians had acquired Code 11 from the US embassy in Rome so each and every one of Fellows reports landed on Rommels desk within eight hours of transmission, giving him a better understanding of the British deployment than many of the British formation commanders had. Fellers hyper critical reports on the failures of the British are doubly ironic as would the British have performed so badly, or Rommel so well had Fellers intercepted reports not been so detailed? Triply ironic is that Fellers belief the British were about to collapse through incompetence, poor leadership and poor moral were actually in accurate and gave Rommel a false sense of superiority that eventually led to him over extending while attempting to give the British that one final, fatal blow that Fellers predicted would do them in.
Could be worth what if of its own. What if the British didn't provide access to Fellers, what if Fellers concerns on the security of the code had been listened to, what if the Attaché had been a less anti British individual or one who had been more conservative with the information provided in the reports? But for this intelligence leak would the British have performed better in the Mediterranean as a whole? Would Rommel have been as successful, would British losses of men and materiel been less? Without this fiasco could the British have defeated Rommel on their own, earlier and less expensively? What effect could these extra, battle hardened troops, not wasted in the desert due to an intelligence failure, have made in Italy or France? With or without Pearl harbour, with or without US troops etc?