Germany had to fight britain alone
Britain was the enemy of the volunteers, so naturally they were not going to fight with their enemy, so they stayed out of it.
Germany
Germany hopes to have a empire and navy to compete with Britain and its fears is that russia and France might want to fight Germany
Fighting never occurred in Britain in WWII, but the Germans bombed Britain (Civilian centers and military bases), and Britain did the same to Germany. Also, there were exchanges of artillery fire over the English Channel.
Germany had to fight britain alone
Germany
Germany, Japan, and Italy.
Germany was conquering all of Europe. It wanted to take down Britain because basically, Britain was just standing in their way of World Dominance.
Help Britain fight Germany
Lend-Lease Program
Britain was the enemy of the volunteers, so naturally they were not going to fight with their enemy, so they stayed out of it.
Germany, France, Britain, Russia
Germany
The US did not have any standing agreements to aid Poland in the event of an invasion, France and Great Britain did. There was no need for the US to pick a fight with Germany just for the sake of fighting.
The Triple Entente (Britain, France and Germany)
Lend-Lease