As a seller, all but one of my problems have been on an international shipping.
Unfortunately, Post Offices in various countries do not play well together, and, personally, I think that it is only fair that the risk be borne by the buyer rather than the seller.
The alternative, with private carriers, is a much higher shipping price, again, the buyer's problem, not the seller's.
Yesterday a buyer in Australia referred to an "international economy" rate from FedEx, which might be GREAT if it is available, because their tracking is so good.