It is clear that the Eritrean state does not end at the borders of Eritrea. For years it has exercised control over its diaspora. Threats and harrassment are one means. Another is control over state resources: if you refuse to pay the 2% tax you will be denied help with anything from a new passport to a birth certificate.
In this article Tricia Hepner attempts to answer this question: “How does the state act at home and abroad to limit, repress or destroy interventions it deems threatening, while reasserting its centralized power through transnational institutions?”
You can read the article here Transnational governance and the centralization of state power in Eritrea and exile