Interning the French fleet keeps Indochina outside Allied protection

The counterfactual depends on Britain tolerating Japan's occupation of Vichy Indochina long enough for Tokyo to turn toward the Dutch East Indies. That becomes harder if major French ships have joined Free France and can be sent east to defend or recover the colony. Neutral internment in Britain therefore fits the scenario better than immediate Free French service. The distinction shows how the legal and political status of a preserved fleet can matter as much as its combat power.