If by save you mean save them from defeat I would say no. If you mean save by them saving them from a long drawn out war against the Nazi’s then yes definetly.
If we are talking about pre December 7, 1941 the Soviet Union was on the back foot but considering the Germans failure to consider a long drawn out war, long song supply lines and inadaquate equipment for winter battles they were still a way aways from victory. It was definetly an acheivable victory but considering the failures of Hitler to listen to senior generals and military advisors that handicapped the German war effort. Stalin made the same mistakes, but considering the sizeable pool of Soviet manpower and the war making ability of Soviet industry they were mistakes he could afford to make.
In late 1941 the war was Germany’s to lose but a series of wrong decisions from the Nazi leadership doomed their war effort. If Nazi Germany had of mobilised all of their industry for the war effort in 1938 we would of seen a very different Wehrmacht in 1941, a much larger and much more well equipped army that would of crushed the Soviet Union underfoot. Another mistake Hitler and the Nazi government made was not mobilising the women to work in the factories so the men could be freed up to join the army like the Allies did. With the factories working at 100% cranking out tanks, guns and aircraft coupled with the extra manpower of millions of soldiers the Germans could very well of won.
But I suppose thats missing the point of the thread. The German navy in late 1941 was in no posiiton to take on the might of the Royal Navy head on, nor was the Luffwaffe in any state to destroy the RAF, so the invasion of Britain would of been impossible. The British people would of fought on, with the help of their empire in both man power and industry Britain could of fought on more or less indefinetly. With the Canadians cranking out hundreds of Corvette’s a year to escort the Atlantic convoys, Britain would not go hungry. The empire would of fought on and like Churchill so famously said “Never Surrender”. Without the German invasion of the Soviet Union or the involvement of the United States in WW2 there probably would of been some sort of negeotiated peace down the road, because for the forseeable future it was a war neither side could win.
A German general wrote in his diary “after six weeks of war we have inflicted 3 million casualties on the Soviets, in both loss of life and prisoners. If they can afford to keep going with that sort of loss of manpower and life we are going to lose this war” (just for the record that is paraphrasing I cant remember the exact words)
And that was exactly the case, the Red army abosrbed those casualties and kept on going, the factories kept making machines of war day and night. The Soviet war machine was probably the largest war machine in all of human history, when we are talking about ground and airforces the number of men and machines they could bring to the battlefield they could of brought any country they could get to by road to its knees.
What people forget about WW2 is the fact that at any given time no more than 25% of German forces were fighting on the Western front against the Anglo-American alliance, the rest were all on the Eastern front fighting the Russians. So without any American intervention the Soviets would of eventually prevailed.