The simplest way to resolve any international shipping concerns of the seller is to have a contact \ shipping address in the USA that you trust and will work with you reshipping the item overseas. Have your purchase shipped to the USA address for reshipment to you. This doesn't really add much to the cost.
This lets you the buyer assume all risk.
If the overseas buyer is paying via paypal, and you ship the knife to an address other then his/her verified PP address, the seller is still responsible for the knife. The seller is responsible for the knife till it reaches the buyer.