In earlier times prior to the industrial growth of the post WWI and WWII era people usually lived much closer to the source of manufactured goods. While there were many exceptions, such as finished good shipped from other countries and natural resources only produced in remote locations, most of the necessary goods and materials people consumed and on which they relied were produced relatively close to where they were consumed.
We don’t think twice about seeing Made in China or any other country on the good we use. We more likely don’t even notice that the fruit or vegetables we buy at the grocery store were grown in a foreign country then transported by truck, train and ship to us.
In earlier generations factories tended to be built close to where their output would be consumed. Transportation costs were a major issue for many manufacturers.
At one time when you bought a new pair of shoes you likely bought them from a shoemaker in the same or a nearby community. No your shoes are probably made in and transported from another country using materials produced in and transported from several other countries.
Over time as railroads became ubiquitous and transportation costs declined larger factories became regional and even national but the majority of factories remained local or regional. Even today most bakeries and dairies are local and serve only an area 50-100 miles wide. Many serve a single city or even part of a city.
As the transportation network grew and costs declined it became possible for factories and industrial production to make use of materials from a much greater distance. It became possible for a factory in one part of the country to use parts and subassemblies made in other parts of the country or even other countries entirely. Power plants could rely on fuel produced hundreds or even thousands of miles away instead of having to be built near an existing fuel source.
This was made possible by the growing sophistication of the transportation systems; canals, better roads and eventually interstate highways, trucks, fuel distribution pipelines, railroads, larger and more powerful locomotives, electrical and electronic control of both road intersections and rail scheduling and more efficient use of the transport system itself.
Over time both the transportation and the industrial complexity have grown to the point where they are increasingly complex and therefore fragile. If something interrupts the transportation network the industrial complex stops. Today both industry and the transportation systems rely heavily on both electronics and the electrical grid. Damage either one and the transportation system slows or stops.
Petroleum is produced in one part of the world, transported to another part of the world to be refined in fuels. The fuel is moved via pipeline or rail to distribution centers. From the distribution centers it is moved to direct distribution points where it is fed into vehicles ranging form boat to trains to planes to trucks. With increasing efficiency has come increasing vulnerability.
Factories rely increasingly on Just In Time Inventory systems based on the assumption that the transportation network is 100% reliable. Grocery stores depend on a 100% reliable and highly flexible transportation system to maintain their stock levels without having to maintain more than a few days worth of inventory in the store itself. Gas stations use smaller and smaller ground tanks relying on smaller and more frequent fuel deliveries. Virtually all retailers and suppliers have moved to dependence on a the transportation system to minimize their inventory costs. The amount of inventory on hand at any given time in any given store continues to decline as inventory management becomes more sophisticated.
The tradeoff in cost savings and efficiency in all these systems is that they assume 100% reliability of a transportation network which is, itself, highly complex, interconnected and fragile.
Just like the heart and circulation of blood in a living being, if the transportation system stops the body dies rapidly.