Harvard Business School's Working Knowledge has packaged the restructuring of American supply chains after the tariff shock into five charts. That's the whole offer: five visuals, one argument — the playbook US importers built over three decades of low-friction globalization no longer holds.

The timing explains the exercise. Tariff rounds imposed from 2018 onward, and extended since, have rewritten landed-cost math for anyone moving goods into the United States. Sourcing decisions that once turned on a few cents of unit labor cost now turn on duty exposure, customs risk and the resilience rhetoric that boards have adopted as policy.

What does this change for shippers? In practice, everything that sat quietly in the old model. The charts walk through the visible consequences: sourcing shifts away from China toward Vietnam, Mexico and India; inventory builds as firms trade working capital for optionality; and the carrier network adjustments that follow when volumes move rather than vanish.

For forwarders and BCOs, the practical read is that lane selection has become a strategic decision again, not a procurement afterthought. A tariff line item that once rounded to zero now moves total delivered cost by double-digit percentages on exposed categories. That's enough to reopen supplier contracts that had sat untouched for years.

Carriers feel the same force in mirror image. Trade lanes that absorbed Chinese export volume at scale have had to reposition capacity as sourcing diversified. The result is a freight market where the map itself is contested — port calls, transshipment hubs and inland routings all back on the table.

The five-chart format deserves a small note of credit. Academic treatments of trade disruption tend to arrive late and wrapped in hedged prose. This one compresses the reshuffle into something a supply chain manager can read between two meetings. Dry, visual, and mercifully free of forecast promises nobody can keep.

Still, the charts describe a transition, not an endpoint. Sourcing shifts take years to bed in, and each new tariff schedule resets the arithmetic mid-move. Firms that treated 2018 as a one-off adjustment have been corrected twice since.

The forward question — whether the US supply chain ends up genuinely diversified or simply re-concentrated in a new set of low-cost jurisdictions — stays open. On the evidence Harvard assembles, the reshuffling is real, measurable and unfinished; the next tranche of trade policy will decide how much of it sticks.