The experience of living as an expat in an international city such as Zurich is amazing. From learning Swiss German to hiking in the Alps and settling into your new work environment, there is so much to do. But if you are a US citizen living abroad, there is a looming shadow that follows you across every border: the Internal Revenue Service (IRS). The United States is one of the only countries in the world that practices citizen-based taxation. This means that no matter where you rest your head, if you hold a US passport or green card, Uncle Sam…