>bank account or credit card
Cash has been invented. They also don't have mail addresses but still some people suggest sending food.
I supposed a way to give aid. No matter what way you choose the warlords and corrupt governments are going to be huge problem.
The best way to help so far has been private investing. But it doesn't matter if the investor is single rich guy or bunch of average westerners. That's how stock works. But the warlords are again a problem. During the past 50 years, western "help" has done probably more harm than good. But that doesn't mean we are unable to ever do any good. As far as I understand, that UBI idea has been only once for limited time, and it looked like it could be a success.
It would be great if we could incentivize the warlords to behave. We should start from a country that's relatively safe and where the locals can anonymously report if they got to keep the money. Despite such country not being the absolutely poorest one. This should turn out for the best once more restless countries figure out they could be collecting fat taxes from the imported goods. If they just settle down.