It’s a good question, GiddyXRay. How long does Germany have before the US can successfully interfere with a KBF?
Given my recommended openers for Germany and Japan, the USA should start the game on A1 with a destroyer and a battleship on the west coast, a cruiser in panama, and a destroyer on the east coast. The USA will have an average of 40 IPCs per turn. What happens if they spend it all on dropping warships into the Atlantic?
A1: consolidate Pacific fleet in Panama canal, buy 1 carrier, 1 battleship, 1 submarine for east coast (40 IPC)
A2: bring Panama fleet to Atlantic, land fighters on carrier, buy 5 destroyers for east coast (40 IPC)
A3: buy 4 submarines, 1 carrier for east coast (38 IPC)
US now has an Atlantic fleet with 2 BB, 2 carriers, 2 fighters, 1 cruiser, 5 submarines, and 7 destroyers. After adding two more fighters to the fleet en route, the fleet will have 23 HP and 49 offensive pips – more than enough to crush even a reinforced German fleet of 2 carriers, 4 fighters, 1 BB, 1 CA, 2 DD (11 HP, 31 defensive pips). Of course, first the US has to get there.
On A4, the American fleet can move to the coast of Morocco. On G5, the Germans use 2 destroyers to create a ‘screen’, blocking off the American fleet from meeting up with the main German fleet.
On A5, the American fleet moves into the destroyer screen in, e.g., the English Channel, and can’t reach the main German fleet in, e.g., the North Sea.
Finally, on A6, the American fleet will crush the Kriegsmarine – but that’s after Germany has been able to land token attacks on Britain on G3 and G4, and major attacks on Britain on G5 and G6.
The USA could try building in the Atlantic for only two turns – but if the US fleet sails with only a two-turn buildup, then Germany may be able to match that buildup by, e.g., saving up for a third carrier group. Germany could probably even build a fourth carrier if Japan wants to send a pair of Japanese fighters over to the Baltic.
Meanwhile, Japan should be pounding on America’s back door, taking Hawaii and threatening San Francisco – if the USA literally abandons the Pacific and then drops 100% of its IPC on an Atlantic navy, then there’s no reason why Japan can’t shuck four transports a turn into Alaska and Western Canada.
So, yes, the USA can certainly cut off the German attack on London – but not fast enough or reliably enough to make this a dead strategy.