This document discusses threat analysis and strategies for securing voting systems. It outlines potential threats like attacks on voters, candidates, or polling infrastructure. Different means of representing threats are examined, like attack trees that break down goals and methods of attackers. Challenges in threat analysis include the variety of possible attacks and dimensions to predict. The document also considers "unthinkable" attack scenarios and recommends strategies such as using independent expert teams and red team exercises to test systems and procedures. The conclusion is that threat trees can help identify flaws but unforeseen circumstances remain a challenge.