The former Wallies are knocked all the way back to Britain, while the USSR occupies Europe, and possibly also the Mediterranean.
Meanwhile, the PRC invades Japan with Soviet help, and creates an Asian communist commonwealth under Mao's aegis. Later on, a split still happens between them and Moscow.
Mccarthyism gradually grows in the United States, resulting in the erosion of civil liberties and the nefarious trade of freedom for security. A certain moustached old man takes over, cameras and screens with his image are installed on every street, society is reformed... and we have always been at war with Eastasia.
Just kidding. Most likely, the Soviets estabilish puppet states all over mainland Europe behind the pyrenees, only to lose them later, Tito-style. The US focuses on defending the Americas from communist infiltration until they can work up their arsenal, while the situation in East Asia grows only a little different from OTL.