I certainly agree that “act of war” is not well defined in international or domestic law. I think it's inappropriate to deal with any of these matters as a question of deemed renunciation. The notion of a deemed application for renunciation is the thinnest of legal fictions, which is designed to narrow, to the greatest possible extent, the amount of due process that is involved. This is a much more streamlined process in our current Citizenship Act than even revocation proceedings. Revocation proceedings take place when there is a suspicion that an individual has obtained citizenship fraudulently, and there is more process related to that. So the notion of adding any number of potential crimes vaguely, moderately, or well defined to a deemed application for a renunciation process seems highly problematic.
On April 16th, 2013. See this statement in context.