Here’s a piece of guesswork about moral psychology. Suppose you are aware that purchasing antiquities without a clear provenance might result in money going to organisations like Hamas and ISIS/Islamic State. Suppose you've seen remarks like this one from Conflict Antiquities:

[P]otential buyers need to ask themselves one key question: ‘What are the chances that my money is going to buy bullets?’ (Or, as Paul Barford rephrased it, ‘what are the chances that they are not[?]’)

Wishing to do good rather than ill, you choose to spend your money elsewhere. And how do those wishing to do good in the world spend their money? One way, you might think, is to donate it as foreign aid. Except that you might have seen another recent blog post, this one from Civitas...

Leading development economist Paul Collier [...] finds that 40 per cent of African military spending is inadvertently funded by aid. Over 11 per cent of development aid “leaks into military budgets”. Because military expenditure by African governments is influenced by both aid and the level of military spending of neighbouring states, they conclude that “Where aid is common across a region, as in Africa” it “inadvertently has the effect of escalating a regional arms race… In Africa military spending is almost double its level in the absence of aid.” Britain’s foreign aid has exacerbated the instability politicians claimed it could solve.

If you were of a hard and cynical mind, you might reason like this: if I buy murkily sourced antiquities, I contribute to messing the world up but gain some antiquities for myself. If I try to make the world a better place through charity, I contribute to messing it up anyway (as I already do through my taxes), and gain nothing for myself. So trying to do the right thing here is futile and unprofitable.

I don’t know whether anyone does reason like that. Certainly it’s reasoning of doubtful soundness. Still, it reaffirms that the task of discouraging trade in dubious antiquities is one that isn’t enjoying the most helpful of wider contexts.