I can't find the source, but I remember reading about how there's a lifecycle to stolen art. The thief sells it to a sketchy art dealer at a huge discount. The sketchy art dealer then sells it to a more legitimate dealer at less of a discount. Then, it either goes to a legitimate private collector or museum. The length of time between each step can span decades, but it becomes more valuable at each transition.
Give it enough time, and will anyone even know who the rightful owner is supposed to be? I have a feeling van Gogh's fame will probably outlast the Netherlands, let alone a claim of legal ownership by one museum.
I don't think many people acquire stuff on the basis it might be easily resellable to people who aren't criminals around the point the Netherlands and its national museums cease to exist.
