> it would be possible (albeit weird and unsustainable) for everyone in France to be retired, so long as say the Philippines was young and working and French retirees owned all the shares in Philippine companies

That is basically the same situation, but you are replacing local people that see the retired ones with remote people that can refuse to send any money and won't even see old people starving.

A strong military can make the situation more sustainable, in a highly immoral way. But that again isn't new, you can enslave people near you too.