Trade routes change slowly and for large reasons: a canal opens, a war closes a strait, a chokepoint silts up. This one changed because underwriters repriced.
Beginning last autumn, marine insurers raised war-risk premiums on a corridor that had carried a substantial share of Asia-Europe container traffic since the canal’s expansion. The increase was not dramatic on a single voyage. Compounded across a service loop and a fleet, it was enough to make the longer route cheaper.
Carriers adjusted quietly, as they generally do. Schedules were extended by eight to twelve days. Rotations were redrawn. Two alliances redeployed capacity to absorb the additional sea time, which absorbed the slack that had been keeping spot rates soft.
The consequences arrive in October. Retail inventory planning for the winter season was set in the spring on the old transit times, and the difference between an eight-day and a twelve-day extension is the difference between a late shipment and a missed season.
Ports at the far end of the new routing are the other pressure point. Two of them were operating near their practical berth limit before the change and have now absorbed additional calls without additional cranes.
None of this is a crisis and most of it will be absorbed. It is worth noticing chiefly because of how it happened: no government decided anything, no treaty changed, and a route that had held for a decade moved because a spreadsheet in London said it should.