I'd like to propose a workaround for international buyers, especially buying from the US when shipping with USPS -- request the package be shipped with "Registered" service, which costs about $15.
Registered is the MOST RELIABLE USPS service, and is honored by ALL countries which provide a similar reciprocal service (it is mostly known by the same name). It is an
additional service on top of whatever USPS shipping option you select, so you can have USPS First Class + Registered (works cheapest), or USPS Priority Mail + Registered, and so on. US sellers will pay an additional ~$15 for the Registered service. Tampering with a Registered package is a Federal offence in the US, and almost all over the world, and (in the old days) a register with signatures was maintained as the package changed hands.
Note that USPS PO may
discourage you from using this service in order to sell you more expensive services, and the fact that the PO has to do more electronic paperwork, and additional processing of the package (stamping the tape seams, see below). The PO may also tell you that Registered is only guaranteed till the package leaves US shore, which is true to an extent. However, if the recipient country has
similar reciprocal service, rest assured the package will make its way either to the buyer or back to the seller. NO EXCEPTIONS, REGISTERED IS HOT STUFF IN ALL COUNTRIES.
This also means an increased burden on the US seller -- he/she not only has to physically handover the package to the PO, but also follow certain packaging guidelines (it cannot have plastic tape, as every seam will be stamped by the PO for tamper-detection). Please see the
thread in consolidated sticky list above that explains this process.
In a nutshell,
total peace of mind and most economical way to ship USPS international packages = USPS First Class Package + Registered service