Even isolationists won't keep the US out of the war if there's unrestricted submarine warfare and something that is similar to, if it isn't exactly an attack on Pearl Harbor.
Hello,
it was unrestricted sub war, even us destroyers got sunk (Reuben James) or attacked german subs...
the interesting question is:
what if the japanese do what they did in late 1941, but germany do not declare war....
will the USA start a war with germany if it is in a war with japan?
Can someone avoid this - if it is avoided, what consequences will this have for the british?
Could the flow of materials and ships to the british island be lessen, because the USA concentrate at japan (no germany first-strategy?)
The only significant points are:
let roosevelt die in the 20ties...
another president that is not so eager to enter the war will be not so kind to the brits, so these have no money to pay the toys... if this president hates communism, he will not support the russians...
so basically you cange two things with it:
a.) the british empire suffer heavy, cause they have not the money to pay the weapons - if you like sink one of the gold-transporters, so the british loose this money too... without cash the british cannot act as they did in real life... (lesser destroyers, lesser production, lesser P40, guns, etc)
b.) the russians recive nothing - that hurt them really. So less tanks, planes, supply, cloths, shoes, jeeps, trucks (!), locomotions... even if they are not ready in 1941 or early 1942, the russians knew that the usa will send this stuff. Also no british support (they have no surplus, cause they cannot pay the usa for their own stuff)
you do not change:
usa rearm fast - from 1938 on... every president will do this, cause the depression need it...
the japanese will have similar problems like the british... they will have no money left in a few months... so even without an embargo, they need to attack...
how serious are the changes and how do they influence the war in europe?
with the USA not in the war (and as important: only cash-and-carry) the british are seriously weakened. Esp. if the japanese do like they did historically, they are in real trouble - not to be conquered - but they have to decide what they need. If it is ships, they cannot build much bombers - because both are important they will have less from both - so the germans have more possibilities (or less losses) in 1941 and 1942.
the russians will be beaten in 1941, but not out of the game, their comeback will be much later and way bloodier... without the support of the usa they cannot mount so many attacks - lesser attacks could lead to leningrad taken (in august 1942)... so even a stalingrad could be avoided (stalin could shift all his strength to the nord - so he could be weak at both locations)
how serious this will change the war in the east if leningrad falls before winter 1942/43 and stalingrad will be no encirclement?
the russians have enough chances to hit the germans in the south, but the loss of leningrad (if someone want to go this way) improve the supply situation a lot.... so more trucks for the central and the south (you can ship much more supplies by sea transports, save from partisans)
with this the german frontline is stronger in the north and the central...
but - with the usa in the war - say december 1942 (for example, the fall of leningrad and stalingrad in late november together with a unsucsessfull el-alemain-battle, so the usa realize that the germans really could "win" this war) this will change.
So another interesting question: how quick can american support improve the russian situation? 6 months? 12 months?
Interesting for sure...