Wiki has an interesting discussion of the definition of "Arab:"
Kottke does overlook one essential point. The Moomins are definitely Scandinavian.
Most people who consider themselves Arabs do so on the basis of the overlap of the political and linguistic definitions. However, some members of groups which fulfill both criteria reject the identity on the basis of the genealogical definition; Lebanese Maronites, for example, may reject the Arab label in favor of a narrower Phoenician-Lebanese national identity (although Maronites originate from the Syrian interior and Phonecians lived on the coasts of Syria and Lebanon), as do many Coptic and Muslim Egyptians who embrace the continuation of their ancient heritage. Groups using a non-Arabic liturgical language are especially likely to consider themselves non-Arab. Not many people consider themselves Arab on the basis of the political definition without the linguistic one—thus, Kurds or Berbers do not usually identify themselves as Arab—but some do (for instance, some Berbers do consider themselves Arabs, and Kurds are cousins of the Persians).