A 1921 Royal Navy strike on the U.S. fleet

How could a British admiral try to 'Copenhagen' the U.S. Navy after failed Washington negotiations in 1921?

Ambush the fleet at the Panama Canal, strike East Coast infrastructure, and use imperial bases to keep the American force divided.

The first problem is concentrating the U.S. Navy where Britain can defeat it instead of fighting across two oceans. A planned American fleet problem in the Pacific provides the opportunity: submarines wait on the Caribbean side of the Panama Canal while the battle fleet moves south from Canadian waters. British carriers spot for bombardment attacks on East Coast bases and industry, while damage around the canal traps the surviving American fleet in the Pacific. A Mediterranean force could then reinforce Singapore if the Americans sailed the long route west. The scenario depends on surprise and Japanese cooperation, but it demonstrates how bases, canals, and fleet concentration mattered as much as individual ship strength in 1921.