These governments could also maybe ask where the money to buy the passport comes from. Then you could check if those investments have any ties to known drug tra

These governments could also maybe ask where the money to buy the passport comes from. Then you could check if those investments have any ties to known drug traffickers. That should certainly raise some red flags at least. Same thing with ISIL funders, ask the person to explain where the wealth comes from and require that the business has to have been audited by the local authorities. It's not perfect, but then at least someone might look into suspicious transactions to known terrorists.