Yugoslavia

Yugoslavia is a small country located in the Balkans situated in between Italy, West German command, East German command and Greece. As a neutral country, it is hemmed in from almost all sides by Axis countries. Yugoslavia should be played similar to Greece with the exception that it is even more of a recommendation to join the Axis. Concentrate on using an infantry force with lots of rocket infantry to counter tanks. Unlike Greece, Yugoslavia has no natural defensive choke points. However, if the Axis is sufficiently distracted enough, Yugoslavia is within easy striking distance to vital East German cities located in Czech region which they can take before East German Command can muster up its forces.

Join Allies
Not a recommendation for newer players, especially if the war is going relatively well for the Axis forces (i,e. France fell in the first few minutes). Yugoslavia would just get rolled over by Axis tanks before they can bring a significant army to bear. If the war in France is sufficiently bogged down and Allied victory seems certain, then Yugoslavia can strike at southern German cities. Make certain that you do not overextend and leave a significant defence behind to protect your infrastructure with lots of sandbags, tank traps and bunkers.

Join Axis
Build up your economy, and invest in the rockets tech early. Build up an infantry force comprised of machinegunners and rocket infantry as the bulk of your force, due to their their cheap research, manpower and supply cost. if Greece turns Allies you can test your army by helping the Axis storm through the Greek cities. When operation Barabossa begins. Use your significant infantry force to protect the flanks of Axis tanks and take the Russian cities, freeing up the Axis tanks to destroy key Soviet infrastructure and ending the Soviet threat forever.