Holtzendorff had acknowledged that the United States might enter the war but expected submarines to prevent its army from reaching Europe. Troop movements were exactly the traffic the Allies would prioritise for convoy protection. Troops could also travel in fast passenger liners rather than in an average slow merchant ship. The example exposes the danger of applying general merchant-tonnage assumptions to a specialised and heavily protected military transport task.
Notable Point · 52:09-52:36
Why troop convoys defeated the transport forecast
American troops were the cargo most likely to receive convoy protection and travel in fast liners, undermining Holtzendorff's assumption that submarines could stop their passage.