I think there's always a controversy
Look at when the US shot down a satellite recently. Russia and China both argued against it even though both had shot down satellites for far less valid reasons. Countries like to argue for their rights just to make sure they maintain them.
Any request made by an entity wanting that request to go through is couched in language to ensure the request is considered by "the world" as the morally proper way to go. Nobody ever says "give me items because I want the cash". A lawsuit with a huge cash settlement is always argued that the amount is high "to prevent pharmaceutical companies from doing this again to someone else" not because "I like the idea of having lots of money"
It is human nature and the nature of community action.
Let's take North Korea. North Korea has a long history of starving its civilians and killing them off. Let's say North Korea needed lead for its nuclear reactors and the world had put an embargo on lead exports to North Korea because of this. Now let's say there were 10 large lead statues created in North Korean in 1,000 BC that were currently in Britain at the museum there. North Korea suddenly demands their return because "they are cultural treasures" despite many other North Korean items being ignored in other parts of the world.
Should Britain send them back, knowing their destination is the melting pot? The North Koreans don't want them back, and don't want them melted. The North Koreans want food.