The Labour government cancelled the Surrey-class ships before treaty negotiations as a gesture of good faith. This is presented as poor bargaining because ships already ordered could have been offered during negotiations in return for useful concessions. Cancelling them first surrendered that leverage without requiring another power to give anything back. A later counterfactual suggests that trading away Surrey and Northumberland at the table might have secured another 10,000 to 15,000 tons of light-cruiser allowance. The point is less a precise alternate treaty than a lesson in preserving negotiable assets until bargaining begins.
Notable Point · 54:19-55:50
Cancelling Surrey surrendered treaty leverage
Cancelling two heavy cruisers before the London Naval Treaty removed bargaining assets the British delegation might have traded for concessions.