I have tried watching the first episode twice now, maybe a third will help.
I watch a lot of World War II documentaries plus show that show off all are military hardware. In WWII, They built a factory that was 3.5 million ft so they could crank out thousands of B24 bombers, the factory name was Willow Run. Ford and Wily combined to make 650,000 4 wheel drive jeeps. The billions of bullets and millions of bombs and shells turned the US in the worlds only super power. The amount of car factories and other factories that were told to mfg all kinds of parts and new aircrafts, tanks, Aircraft Carriers, Destroyers, Battleships, Subs. I could go on but they all did their jobs and produced more than anyone thought was possible.
We out spent every every other country by a huge amount and created the largest most technically advanced military that the world had ever seen.
Compare it to today and we could wipe out the whole planet if we wanted. Russia could team up with China and who ever else and would be destroyed. For an example, we have 22 aircraft carriers and Britain is in second place with 4, China has 2 and Russia has one.
Our sub fleet alone could wipe out China and Russia and anyone else.
When you research this stuff it is mind boggling. Did anyone know that the US has 800 basis around the world? It goes on and on and it is cool to learn about it all.