Container Shipping starts earlier.
Start with the wooden boxes used by the Little Eaton Gangway (1795), or the Liverpool and Manchester Railway (in 1840 the boxes were made of iron), or have the Railway Clearing House (1920s) standardize its boxes and make the designs available to everyone. This could allow rapid shipping before WW2. Make the containers stackable to allow for larger cargo holds.
By making cargo transfer faster, ships are underway as much as possible, meaning the transportation costs are lowered, and loading costs are lowered. To give an idea, in 1956, loading a ton of cargo by hand cost $5.86. Loading a ton of cargo via the container method dropped the cost to 16¢.
By using sealed containers (to prevent theft), losses en route can be minimized (especially whisky, one of the first cargos to be in sealed boxes). Using a standard container means ships can be designed to handle multiples of that container, rather than needing to worry about custom sizes.
This will drop shipping costs and times, allowing a factory in one country to supply goods to another country cheaper than the other country can build itself. From there, you need better communication to coordinate the shipments to the nearest hour.
Here is the relevant wiki articles:
Containerization
Malcolm McLean
