Sorry folks... this took so long to respond plus, this is rather long response.
True but then German industry would have been moved east or underground limiting the effectiveness of RAF raids, it would have come down to how long the RAF could have sustained the losses for diminishing returns.
The biggest problem with Japan and Germany was, neither had prepared their industries for an extended conflict! Both had anticipated relatively short campaigns, six months to a year at most. When neither Germany nor Japan were able to convince their enemies to just give up rather than fight such a powerful country, such as themselves. Their defeat was a foregone conclusion... they believed their own propaganda! When Britain did not surrender quickly, that became problem. Hitler had a great idea.... let us attack and take out the Soviet Union while we wait for a solution about what to do with Britain. (Hitler was living in LaLa land!) The Japanese complicated Hitler's plans when they attacked the USA at Pearl Harbor. Hitler had planned to keep America out of the war as long as possible.
The Germans felt they had located their industry as far as it was practical (transport ability was a consideration, also). Any further east and they could run into problems with the Russian Air Force, especially if the Soviets moved west or, if the Russian AF developed medium or long range bomber. Once the USAAF and RAF had new long range fighters to escort the bombers, all of German industry was in peril. There were 13 oil facilities that converted coal to oil products in the north-eastern Rhur Valley. These thirteen facilities produced almost half of Germany's oil AND, 90% of their aviation fuel! After several attacks only one facility could produce a small fraction of their oil produced before the bombing campaign. Over all the oil production dropped by 98%!!!!! While the 8th AF B-17s worked over the Ruhr Valley the 15th AF B-24s went back to destroyed Ploesti (with fighter escorts), the refining and converting oil products once and for all. Ploesti's its oil production dropped by 52%! Then there was little fuel for the interceptors, training pilots or, armored units. The Luftwaffe could only scramble to intercept bombers when they were going to attack priority targets such as important cities, military targets, etc. The Luftwaffe no longer control the skies above Germany.
The industry placed underground is not a 'cure-all' either. Underground factories need railroads to receive and ship their goods. The English mathematician Sir Barnes Wallis the one who was a major part in the design of the Veckers Wellington bomber, the skip bombs (the dam busters) and, the designed the Tall Boy bomb, etc... was the first person to realize that the seven major railroad junctions dominated rail movement throughout Germany for the remainder of the war. It was over a year before the Allied air forces accepted the theory. Once the junctions were destroyed, the rail system lost its value. The Me-109, 262, engines, tank parts, etc. could not be put together from their original parts production point to their final or destination where the parts become a weapon system! So when people say, "strategic bombing was not effective," tell them about these facts about the attacks on railroad junctions.
The LL Locos and rolling stock was minescule compared to the pre-war Soviet stock.
The LL locos were not even shipped until 1944 and thus were of no help at all up until late 1944.
If you wonder why the USA dragged its feet in supplying the USSR weapons and support equipment to the USSR, don't forget the USSR and Germany signed an agreement to divide Poland when Hitler ordered his military to invade Poland. So, while Germany got the lion's share of the blame for the invasion, the USA, France and, the UK all considered the USSR an enemy also, because its alliance with Germany. So there was little or no sorrow or sympathy for the USSR on June 22, 1941 when the war started on the eastern front. The USA and the USSR were allies of conveniences. Both knew the governments were opposite in values and the alliance would probably not last long after the war.
The USA gave a total sum of $46 billion to the countries of the 42 anti-Hitler coalition. The lion's share of deliveries was given to England -$30.3 billion (in 1942 currency). The Soviet Union received defense technology and equipment in the sum of $9.8 billion, France $1,4 billion and, China $631 million. The USSR was offered money from the Marshall Plan but, Stalin turn it on behalf of the USSR and countries of the Warsaw Pact.
The USA shipped 2.3 million tons of steel to the USSR during the war years along with 62,500mi or 100,000Km of railroad tracks. (The USSR and USA use the same gauge and design of the rails.) The US Navy contributed 595 ships! That included (in the winter of 1942) 4 icebreakers, also 28 frigates, 105 submarines, 77 trawlers, 22 torpedo boats, 140 anti-submarine vessels and, others ships. The USA also sent soft goods deliveries of 3.8 million tons and also included 15 million pairs of army boots... and "NO," they were not designed to protect the feet during Soviet winters. The USSR received a total of 229,000 tons of aluminum or 56% of the 408,928 tons, the Soviets used during the war. This was because Aluminum Company of America (ALCOA) had a virtual world wide monopoly on the materials to make aluminum plus, the technology of how to produce it efficiently. The USA offered the USSR the technology to produce higher quality aviation fuel. So the newer aircraft engine designs could operate at higher altitudes and at higher speeds. The lack of refinement of the Soviet aviation fuel was a major contributor to the Soviet fighter designs of being good at lower altitudes but, could not compete with Luftwaffe above 4,575m (15,000ft).
The cargo ships started their trip across the Atlantic Ocean from America and after the U-boats and German planes attacked and sunk a fair share of the cargo ships, they made it to the UK. The run from the UK to Murmansk cost more than than 50% of the cargo ships that left the UK throughout the war. (Does this mean the return trip cut the remainders by 50%? -most likely!) The sad news is, merchant mariners reported back, they never went to any port where the people were less appreciative and less hospitable than the people they encountered at Murmansk. Considering the number of ships that left America only a very small percentage would make it to Murmansk and back to the USA.
I wish I could find statistics on how large the convoys were when they left the USA and the percentage lost to the UK. Then the number of ships that left the UK and then arrived at Murmansk. Then repeat the process back to USA.... it would be an interesting project.