A lot of exchanges I'm in are worldwide, but shipping is obscenely expensive when you go outside of your country so people get crafty and send things via local merchants. Most countries have their own big online stores that people can shop at if shipping costs are a big issue, and they tend to accept major credit cards regardless of the country it was issued in. The upside is that many of them also offer free shipping to your gift recipient! I think the biggest barrier someone might have to work around is reading Hebrew on Israeli sites to send you something back!