Aircraft range and the availability of bases limit attacks on Romanian oil. Securing suitable Mediterranean airfields first requires enough naval strength to contain or defeat the Italian fleet. British forces assigned to watch Japan reduce the strength available for that Mediterranean task. In this counterfactual, changing Japan's alignment alters those deployments and makes the proposed bomber bases possible. The additional force matters through that sequence of commitments and access to bases.
Notable Point · 2:02:07-2:03:05
How commitments against Japan limit the route to Romanian oil
The closing strategic argument connects British commitments against Japan to Mediterranean sea control and airfields within range of Romanian oil.