Equipment from LL such as tanks, aircraft, trucks, etc, etc, etc, would have little direct impact on such a situation. But......if the Soviets don't have to produce as much, or any, of the items received from LL, then they can devote resources elsewhere and starting in 1943, they did just that. Gross investment in their economy showed a positive number for the first time since the war began, and public outlays (money devoted to non-military areas of the economy) rose dramatically. It's quite possible that Stalin would've been on the
receiving end of an October Revolution had things continued the way they were headed....
Without going into an endless diatribe about a complete inventory of what was sent, several items stand out as being crucial.
We are all used to reading the accounts of the Soviet juggernaut rolling across the frozen steppes of the Ukraine and Byelorussia, and finally Operation Bagration pushing the Nazis back into Germany, but how was this accomplished? There are several reasons, none of which are more important than the Soviet will to defeat the Germans, but that might not have been enough.
The first singular item is the GMC "deuce-and-a-half"...tens of thousands of them. Soviets continued to produce their own trucks right up to the end of the war, and certainly could have built enough trucks to satisfy army use. However, in doing so, how many less tanks and other equipment would the Soviet army had to do without? Lots. US trucks were plentiful, ruggedly built, and without them I seriously doubt we would have seen too much Soviet 'blitzkreig' overrunning thousands of sq. kilometers of German-occupied territory in stunningly short amounts of time.
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