Pulling out of Eastern Europe is a deathtrap! But seriously, you’re screwed if you did and screwed if you don’t since you’re know forced to defend two separate territories along with the unbearable 3 IPC loss. But anyways, Western Europe is probably the most feasible and the most advantageous of all the territories to take with USA and UK. But if you can position your transports correctly, you can strikes all German territories at once depending what is the most heavily under-defended.