Bob, in country A, sends Alice, living in country B (one of the most corrupt countries in the world) a gift by air mail: some non-prohibited good stuff of a total weight 10 kg which will make Alice very happy. The customs declaration/consignment note lists all items/weights diligently. The parcel is insured — Bob will get compensated by country A's post if something goes wrong.
The tracking shows that when the parcel left country A it was still 10 kg. But the very first record in country B (at the customs) shows now only 5 kg. There are no tracking events while in transit between A and B.
Alice, upon receiving the parcel, demands that it is weighed, opened and the contents are documented on an official report. This is done and now she has legal proof of the loss.
Now, whereas the items could have been stolen anywhere in transit between A and B, there is a pattern of incidents like this occurring in B. Allegedly, and according to some insider's info, the corrupt customs of B feel free to open parcels, take whatever they like without an official record, and then weight and register the incoming parcel.
Bob files a claim with A's post and gets his compensation.
As for a member of the Universal Postal Union, what repercussions will occur for country B? Are they allowed to keep stealing stuff at the sender insurer's expense? Will they face any penalties (e.g. banned from the Union) that would encourage them to hold their customs to account?