You add direct international postage for the various postal zones. So during the listing (or revising) process under the postage heading click on "See options" on the righthand side and select "International postage". The International Postage link will appear below and you keep adding services and postage prices for the world zones. ie.
Europe
Zone 1 - most non-European countries inc Canada
Zone 2 - Oz & NZ, Japan
Zone 3 - USA.
