How instrumental was the Lend Lease program and aid to Russia to allied victory?
Did it make a difference to the final outcome or would the result have been the same regardless?

Quite instrumental IMO. I'll reply again with a fuller response in due course.

It is my opinion that Lend-lease was vital to the existence of the USSR in WW2. Not from the perspective of AFVs and aircraft - the Soviets provided the vast majority of those items for themselves and in any case, the Soviet built items were generally more effective than the US/UK built ones.

The real area where Lend-Lease made all the difference was in logistics. For example, the US supplied 429,612 soft-skinned vehicles to the Red Army. This aid was vital in allowing the Red Army to transport logistical supplies and troops over large distances. It is said that the existence of Lend-Lease allowed the Soviet soldier to have at least one meal a day.

Moreover, there is evidence to suggest that Lend-Lease also kept the Soviet railroad system operational. Without this, it would have been very difficult for the Red Army to move large numbers of men and equipment around, thus making it very difficult to organize large-scale operations. For example, Lend-Lease supplied 92.7% of railroad tracks and 81.6% of all locomotives.

Without Lend-Lease it is my belief that the Soviet Union would not have the necessary logistical infrastructure in place to repel the Germans. In short, it proved instrumental in their eventual victory. Large scale operations such as the counter-attack at Moscow, Stalingrad, Kursk and Operation Bagration to name some would have been impossible to mount otherwise.

None other than Gheorgi Zhukov himself is on record stating that Lend-Lease was 'indispensable' to the Soviet war effort.

http://lend-lease.airforce.ru/englis...ents/index.htm
http://www.o5m6.de/Numbers.html
http://orbat.com/site/sturmvogel/SovLendLease.html

Originally Posted by Doppleganger

Without Lend-Lease it is my belief that the Soviet Union would not have the necessary logistical infrastructure in place to repel the Germans. In short, it proved instrumental in their eventual victory. Large scale operations such as the counter-attack at Moscow, Stalingrad, Kursk and Operation Bagration to name some would have been impossible to mount otherwise.

As the main supply route into the Soviet Union was via the Arctic ports, this raises a number of important issues.

Could Germany have won the war if:

a) the West had been isolated as discussed in another thread.
b) If the transport infrastructure inside or leading from the Russian Arctic ports had been destroyed, overun or blockaded.
c) If the entire Kriegsmarine, supported by air cover from Norway, had focused on the Arctic rather than the Atlantic

If b) perhaps the most sensible policy should have been to concentrate the Blitzkrieg or bombing in the North, not to the oilfields or main cities.

I have mixed feelings about all this, I think it was right to send aid to Russia but never once did I ever see any picture or newsreel shot of that equipment on a battlefield. I can't but help but wonder if it was all melted down and used to produce Russian weapons

Originally Posted by LeEnfield

I have mixed feelings about all this, I think it was right to send aid to Russia but never once did I ever see any picture or newsreel shot of that equipment on a battlefield. I can't but help but wonder if it was all melted down and used to produce Russian weapons

Here is one for ya...

American lend-lease trucks mounted with Katyusha multiple rocket launchers

Supply vehicles and bulk materials aren't the most prestigious part of an arsenal, hence few photos, but they are just as important as tanks and aircraft. I don't think the Russians were too pleased with the tanks and aircraft that were sent, these were often not suitable for eastern front conditions. However, they liked the Jeeps and particularly the American tinned meat, they called this the 'second front'

Originally Posted by perseus

If b) perhaps the most sensible policy should have been to concentrate the Blitzkrieg or bombing in the North, not to the oilfields or main cities.

Well they should have made a more serious effort to capture Arkhangelsk and Murmansk. There was a joint German-Finnish venture called Operation Silver Fox that was designed to capture Murmansk and the Karelian railway line but it was beaten back by the Soviets. Had the Germans been aware of just how vital the supplies coming through both ports were I think it's a certainty that they would have devoted far more resources to capturing both cities. But then hindsight is a wonderful thing.

Denying either or both ports to the Allies would have had dire consequences for the 2nd World War.

http://en.wikipedia.org/wiki/Operation_Silver_Fox

Actually it seems the main supply route wasn't through the Arctic so perhaps it wasn't that critical after all.

Delivery was via the Arctic Convoys, the Persian Corridor, and the Pacific Route. The Pacific Route was used for about half of Lend-Lease aid:

http://en.wikipedia.org/wiki/Lend_Lease

On the other hand perhaps the latter 2 routes were only opened up late in the war by which time the result was a foregone conclusion

Originally Posted by perseus

Actually it seems the main supply route wasn't through the Arctic so perhaps it wasn't that critical after all.

Delivery was via the Arctic Convoys, the Persian Corridor, and the Pacific Route. The Pacific Route was used for about half of Lend-Lease aid:

http://en.wikipedia.org/wiki/Lend_Lease

On the other hand perhaps the latter 2 routes were only opened up late in the war by which time the result was a foregone conclusion

Only about 25% of Lend Lease came through the northern Arctic ports but even that loss may have been critical as the arctic convoys were the certainly the closest supply centres to Moscow and Leningrad. The other point of note is that by seizing Murmansk the Germans would also have controlled the vital Karelian railway line, which would give them the ability to control supplies throughout the whole region.. Finally, the Finns did not fully commit themselves to the attack on Murmansk, making its success that less likely.