A useful counterfactual changes one decision and follows the consequences that arise from it. Earlier events and institutions remain in place unless the new chain of events supplies a reason to alter them. Beatty therefore remains First Sea Lord, while the 1918 unification of Britain's air services still shapes control of naval aviation. This discipline makes later differences in ships, treaties, and institutions causal consequences rather than unrelated inventions.
Notable Point · 1:21:35-1:22:31
How to keep a naval counterfactual bounded
The analysis keeps decisions made before the treaty divergence fixed and changes later events only when they follow causally from the new settlement.