You chose the not-so-good examples, but you.... They are worth talking about, and they are the cases we often cite in order to convince the international community, and especially the United Nations Office on Drugs and Crime, which is reluctant to develop guidelines for this effort.
I can openly say we are in the middle of negotiating a return between Peru and a European jurisdiction, one of the very old cases relating to former president Fujimori. Peru has every right to say, “Give us the money. It's our money under the UN convention. Give it back to us, and it's none of your business what we do with it.” Because we work closely with them, we have made them realize that it's actually in their interest that the money be returned in a very transparent way so that they can distinguish themselves from those like the previous regimes that have stolen. Even in Peru the levels of corruption are such that I would not trust, if the money goes back to the treasury, that it would not be effectively stolen.
At the moment the only instrument we have is soft diplomacy. There is no legal instrument that obliges any requesting states to take any condition. We never talk about conditionality. We talk about modalities for return.
At the moment, you have soft diplomacy and actors such as ours who try to facilitate these discussions. There is, however, as I said, an international process now that we are supporting, led by the UN Office on Drugs and Crime, which is trying to come up with a set of guidelines that would give both countries a common ground to develop monitoring systems for spending of assets on specific earmarked projects, and so on. That is currently where this debate stands. It's not stronger than that, I'm afraid.