The Swiss have historically been so isolationist, they refused to join the fricking UN until 2002. Some of the headquarters you're referencing have been there since the 19th century, they'll be fine.
Isolationist is an interesting way to describe Switzerland: economically they're probably one of the most internationally integrated, and thus dependent, countries in the world.
For good reason, at the Congress of Vienna 1815 the largest powers in Europe signed a treaty that guarantees Switzerland's neutrality. As a result, Switzerland got spared in world war one and two. So far not entering into any alliances has been a very good strategy for Switzerland to ensure peace.