In this projection, an immediate American declaration in February 1942 is unlikely, but neutrality probably cannot survive beyond July. A clash with a German submarine, the loss of a US warship, or a declaration by Hitler could open the European side of the conflict. Mussolini would probably follow Germany, while Japan would then face a choice between alliance solidarity and continued restraint. American merchant ships carrying supplies to Allied ports create another possible trigger. A Japanese submarine, destroyer, or cruiser could sink one on the route to Australia and turn a regional war into a direct American conflict. The exact incident is uncertain, but the growing contact between American shipping and Axis forces makes continued neutrality increasingly fragile.
Chapter · 25:52-27:58
Several incidents can bring America into the war
The projection places likely American entry by summer 1942 through a German declaration, an Atlantic clash, or an attack on an American merchant ship supplying the Allies.