Here are some ideas:

• Rearm Germany and Japan. Why not throw in some nuclear proliferation while we are at it. Maybe South Korea or Taiwan would like to host some nuclear weapons, if they are not already?
• Get involved in a land invasion of Russia, preferably in winter. (A convenient way to do this is to start your campaign in the fall or even late summer, and just assume it will be short.)
• Also plan some Pacific island-hopping warfare.
• Just assume this will not end with the deployment of weapons of mass destruction by any of the parties involved, especially not the world’s guiding light for peace and democracy.