One way Germany might succeed in getting western support in her struggle against Russia might be Poland. Suppose that Hitler realizes that the western powers will not brook another Czechoslovakia - like take over. Needless to say, this is a huge stretch, but let us suppose that the general staff proposes another means to dismember Poland but without getting Germany getting the bad press. Abwehr agents quietly slip across the Polish border and make their way to the Polish - Russian border, and fire upon Russian patrols while wearing Polish uniforms. The Russians are angry and Poland denies everything; Ribbentrop meanwhile offers a non - official partition of Poland - he supplies Stalin with intelligence reports declaring that a Polish sneak attack is in the works. A couple more border skirmishes lead Stalin to believe it's real, despite the fact that Zhukov and others question the authenticity.
Having had enough of Polish lies and confronted with the facts presented by his 'friend' Hitler, Stalin agrees to attack Poland at a set date, September 15, 1939. After the Russians invade, Germany stands with the western powers deploring Soviet aggression. Enraged at being duped into a war by Germany, Stalin decides that after Poland is finished, the time is right to establish a soviet republic in Germany and declares war on them as well. The German army marches into Poland supposedly to 'save' them, and beats the Russians out fairly quickly. Germany grabs the Baltics and Finland jumps into the fray; I imagine that since Britain and France were serious about defending Poland (although ironically, they sailed Poland up the creek after WWII), they would declare war on the Soviet Union. Stalin might retaliate by demanding socialist/communist strikes and civil disobedience in France and Britain.
The end result might end up being that Germany gets most of her eastern empire - with most if not all of the 1914 Polish border being restored - while not souring relations with Britain (who cares about France?). Perhaps America would still provide lend-lease to the western alliance against the Commies? No doubt Japan would jump into the war, too.