I was not referring just to fuel, but rather resources in general as a great collage. What I am aware of is that supply was shipped in and certain strategic resources shipped out via land: rubber etc. As to sources, just google this forum, it has already been discussed. How much? Now that is the sticking point. Records exist that show supply/resources wre moved overland in ever increasing amounts, but they are incomplete. Also, as has been already discussed, you have fallen into a typical American "hole" by thinking trucks are required to move goods long distances. It has been demonstrated many times in history in asia that human pack horses can, and have done, this job. Again, all of this has been previusly discussed in these forums. I don't recal if you participated or not. I can also tell you the discussions were inconclusive. Either you believe the evidence presented or you don't
For me, I've had a mark 1 eyeball on almost that entire route in one of my earlier lives. In the 70's, 30 years after the war, most goods were still being transported on those roads by, wait for it, people. This is in a non-war situation ... extrapolate to war and you can reach your own conclusions.
For someone sitting in Des Moines in 2014 does this seem plausible? Heck no. We americans walk no further than our garage. We need a cart to get our groceries to our car. Pack 80 lbs for 40 miles? Hardly. But for a lot of aisia yet to this day, that is routine. Again, you just have to see it to understand and beleive it. Then you need to take that and multiply it by the one thing asia has in abundance ... population.
I'll share one last anecdote: I was building a refinery in china in 1980. We needed to raise a 100m tall distillation tower. Now in Korea just a few months earlier we used a crane for this. a big one. China didn't have cranes, but they had several villages of people. They had 6" ropes. So several thousand people hauling on 3 ropes raised that tower. I will add to this that on the first day, one of the splices failed and one rope parted. 83 were killed (that I counted) and unknown 100's injured. The next day they had additional 1000's and raised the tower.
You'll either beleive it possible or not. As i said, the last discussion on this ended exactly that way. Take it as you will. It isn't all that big of deal.