France's collapse changed the strategic map well beyond Europe because Vichy authorities could not effectively deny French Indochina to Japan. Japanese forces thereby moved much closer to Singapore and made the base harder to defend. Britain faced that new pressure while fighting in North Africa and replacing equipment abandoned during the campaigns in Norway and France. The defeat of one ally shifted the balance in a distant theater before Japan formally opened the Pacific war.
Notable Point · 38:20-39:13
Vichy Indochina moved Japan closer to Singapore
France's weakness in Indochina let Japan advance into Southeast Asia while Britain was replacing losses from Europe.