Complex sentence: Its proximity to the axis of international trade gives it some advantage over the Panama route; the Isthmus of Panama, however, is significantly narrower, making for a shorter traversal, even if the canal is farther from trade routes.
Split into simpler sentences: Its proximity to the axis of international trade gives it some advantage over the Panama route. The Isthmus of Panama, however, is significantly narrower, making for a shorter traversal, even if the canal is farther from trade routes.