The significance in favor of the USSR for lend-lease is highly exaggerated outside historical research. The short answer is that the USSR would almost certainly still have won, and in fact pretty much already had won by the time that lend-lease arrived in significant quantities. Longer answer to follow.
Mark Harrison the economist historian who specialized in Soviet economic history in the 1990s, gave a bid for the GDP of the USSR in his book “Accounting for War”. We also know the value of all lend-lease (including services which made up a little over 10% of lend-lease). Hence we can see that lend-lease made up just 5% of the GDP of the USSR for the war years.
But looking merely at the value of the whole war is obviously kinda simplistic. People absolutely love to talk about trucks. So we shall do that.
At the beginning of 1941, the USSR had 961,000 trucks, after the catastrophic losses of 1941, the USSR still had 553,838 trucks remaining as per 1st of January 1942.
Below you see a graph shows cumulative percentage of the total amount of trucks used by the USSR after the beginning of 1942. That is to say which portions of available trucks lend-lease made up. Excuse the Danish.
As you can see, lend-lease trucks made up a good portions of available trucks, however at the end of 1942, after Stalingrad had already been surrounded, the lend-lease trucks, made up less than 5% of the inventory, and at the battle of Kursk it made up less than 15% of the inventory. And at Moscow in 1941, there were no lend-lease trucks at all. Also, in case someone has a number of lend-lease trucks which is over 400,000 and just fuming with anger, then you are counting jeeps as trucks, which they aren’t.
In terms of war material, the two most significant categories of material were planes and tanks. Making up over 50% of all military-lend lease. If we start with tanks, like in the previous graph, the one below shows cumulative percentage of tanks which were Soviet produced vs lend-lease, with the added information that they are also divided in categories of Heavy, Medium and Light tanks.
As you can see, unlike trucks while lend-lease supplemented the Soviet production, it stayed around 10% for most of the war, and was for the most part qualitatively inferior to Soviet tanks, firstly because they never received anything as good as the KV-1 or IS-2, of which they produced around 13,000 themselves. Secondly, various design issues (exception being Sherman which was excellent).
Which of the lend-lease tanks did the Russians prefer, and what did they think of the others?
We go on to aircraft, which in my opinion is the most significant category of military lend-lease much more important than tanks and very overlooked. The below graph like previous graphs shows the cumulative percentage of lend-lease vs soviet production aircraft.
As you can see, in terms of numbers, it is slightly more significant than tanks. But most importantly the quality of lend-lease aircraft was excellent. The only issue the Soviets usually had with western aircraft, was that they thought the armament was weak. This didn’t apply to the P-39 aircobra armed with a 37mm cannon. A concept the Soviets applied to their own Yak-9T. Some of the top Soviet aces flew lend-lease aircraft, and Soviet opinion of the aircraft seems to be been generally high, even the Hurricane from which the Soviets drew inspiration for future avionics.
The next most talked about item is probably food. This one in particular is sorta annoying to me, because I have never met a single person who thinks that the USSR could not have won without lend-lease food, who actually have any idea what food was delivered. I do not know the chronology of food deliveries, so you’ll get the totals in million tons.
The USSR produced 590 million tons of food during WW2, lend-lease amounted to a total of 3.86 million tons. That is 0.7% of the food. No matter how you try to angle that, it is not a significant amount. Consider that the USSR produced 22 million tons of meat. I also have the chronological data for Soviet food production if anyone is interested.
While we stay at the civilian lend-lease, please consider that the USSR produced hundreds of millions of pairs of boots, in that context the 1 million pair of boots and 9 million other pairs of shoes is not exactly mind blowing. Same for blankets and a lot of other small items.
I could show you data for train production, but we can dismiss this quite quickly, by pointing out that lend-lease locomotives didn’t arrive until 1944.
Radio deliveries to the USSR also came up to be about 20% of the inventory from the end of 1943.
Conclusion
Lend-lease was no doubt useful, good and all that stuff. However, all these categories shown above represents the parts of lend-lease which made up the majority of lend-lease; the most numerically significant portions. Most other categories than the ones shown, made up a smaller percentage than these.
There is no area in which the USSR were not able to produce equipment, and in absolutely gigantic quantities. Jonathan House, David Glantz, T. Davies, Alexander Hill and many other military historians who have looked at various battles and the war as a whole, agree with me that the USSR would almost certainly have won without lend-lease. The question is of some difference in time and casualties. Though if the USSR had not received more help from the west, they may just have made a separate peace with Germany, and allowed the US and UK to absorb any additional casualties in defeating Germany, which is exactly what they didn’t want to do.
The most compelling point I want you to consider, is that the vast majority of lend-lease arrived after the Soviets had won the battle of Moscow, Stalingrad and Kursk. By the time the first Sherman was put into action on the eastern front, the German army had already been thoroughly defeated and the days of the Reich was numbered.
Some additional notes
All the statistics I have created here, are from my project at Roskilde university where I studied lend-lease statistics for half a year together with my Russian speaking colleague and fellow historian and journalist.
All the statistics are made at the most optimistic estimates for lend-lease and the most pessimistic estimate or data for the USSR. The numbers do not nessesarily represent reality, but represents the absolute logical maximum significance of lend-lease we could demonstrate.
The most common type of ad-hoc argument against my position is from people who do not understand statistics, and so they must resort to random quotes. So I will make a note of it here pre-hand: Zhukov never said they could not have won without lead-lease, that is from an American journalist claiming that some 30 years later, and it’s not verifiable. Khrushchev was not an economist, or a general or worked in material or logistics, even if the often paraphrased quote of him praising lend-lease as war winning was not taken totally out of context, please bear in mind that he had no clue how much lend-lease was delivered, he was a political officer in WW2 and have zero insight into the economic aspect of it.