Where is our strenth

When I was a youngster in the great depression/dust bowl days a great war started in Europe while another continued in the far east that had been going on for all the years I had been alive. There was no great concern for surely the oceans would prevent any attack on the United States. 

Our economy was on rock bottom and agriculture in the plains was fighting to exist.  The United States had one positive thing going for it.  Our manufacturing capability was without parallel.

Our first involvement in the wars was manufacturing and shipping weapons, armament, and supplies to Europe and a clandestine support to China with fighter planes and pilots.  Of course we immediately drew the presence of German U-boats along our east coast to attack our shipments to Great Britain.

An  attack by the Japanese on Pearl Harbor, Hawaii, showed the foolishness of thinking the oceans would protect us.  Luckily they missed our most potent naval weapons.  In hours, we were at war with Japan, Germany, and Italy.  Our position was very precarious.  False security had caused great weakening of our forces and prevented modernization of such as fighter aircraft.  Germany had superior armament to ours in Africa and Europe.  In the Pacific, Japan had us outnumbered many times over.  Our forces in the Pacific were defending themselves with weapons left over from World War One.  The men being drafted to the armed forces or volunteering were very willing and patriotic.  They didn't march very well but many could knock off a squirrel at fifty yards.  After a very short basic training we sent them to fight against soldiers with years of experience.  

With our manufacturing capability, we sent those men out with an advantage; a rifle called the Garand M1 Caliber .30-06 which gave them the fire power of several German or Japanese soldiers.  We needed troop transports and started building them rapidly by welding them together instead of riveting.  We needed airplanes and factories were set up in weeks where planes were completed  every few minutes.  More modern fighters that had been on the drawing board  started rolling off the assembly line and gradually gave us air superiority.  Finally, bombers were built with such great range that the enemy's homeland was not secure.  Our forces prevailed in Europe and the island hopping campaign in the Pacific was brought to a close by the use of the atomic bombs.

The only logical conclusion is that the war was won by our manufacturing capability.  My question is this; "Where is that strength at this time?"  An army does a lot of marching which requires boots.  I don't believe there is a boot  factory in the United States.  Our plumbing supplies all come from another country.  Recently, our Air Force needed an air refueling tanker and a European country was almost picked for a source.  Steel and aluminum works have mostly gone to foreign shores.  China is a major source of our western leather goods.

In case of another major war, where is the strength of the United States?  We have shipped our skills to other countries and rewarded the companies that have done so.  I want to know how our representatives propose to remedy this situation; penalize those who move their factories to foreign shores and reward those that strengthen our capabilities.