A coal-logistics trap for Imperial Germany

What might Britain have done if the United States and Imperial Germany had gone to war over Mexico just before the First World War?

Britain might have stayed neutral while allowing enough coal for the German fleet to cross the Atlantic but not enough to make the return voyage.

A playful counterfactual imagines Britain remaining formally neutral if the United States and Imperial Germany fought over Mexico shortly before the First World War. The Royal Navy could allow enough coal for a German force to cross the Atlantic without ensuring it had enough fuel to return. Germany would then have much of its fleet committed far from home and dependent on overseas supply. The scenario shows how coal endurance could shape strategy without Britain firing a shot.