Why a 1940s Mexican rail-pipeline link changes little

What economic and military effect would an early-1940s rail-and-pipeline link across Mexico have?

Probably little, because railways already provided a cross-Mexico connection and the proposal would largely duplicate it.

The panel expects little added value because railway lines already crossed Mexico between the two maritime sides. A new rail-and-pipeline link in the early 1940s would therefore duplicate existing trans-isthmian transport rather than open the first Gulf-to-Pacific connection. The answer ends before quantifying petroleum throughput, port-transfer rates, or vulnerability. Its conclusion should be read narrowly: the geography alone does not create a major new advantage when a land link already exists.