The episode imagines the fleet counterstroke only after the land campaign has slowed the Japanese and exposed their forces to a larger operational problem. A Japanese fleet moving to support the land offensive would trigger the Royal Navy's approach from Ceylon. British submarines, land-based torpedo aircraft, and American, Australian, or other forces approaching from the south would complicate that intervention. The geography could place Japanese ships between threats arriving from several directions and within range of Singapore's torpedo bombers. It is a conditional outcome, but it illustrates why the plan preserves maritime striking power rather than expending it at the start of the war.
Notable Point · 30:00-30:36
Bring the fleet into a torpedo-bomber threat zone
If Japan commits naval forces against the prepared defence, the plan calls in the Royal Navy fleet and places the enemy within reach of land-based torpedo bombers and allied forces.