A growing number of discussions on geoengineering risks and politics pose the question of how solar radiation management (SRM) might be of interest to security and military planners. National security consists not only of planning for direct military actions between states but is a much broader concept that takes into account when background conditions change with indirect but unexpected results for international or state stability. A general view in the US security community holds that geoengineering (and in particular, SRM) projects are not tightly controllable, and therefore are analogous in some ways to biological or chemical agents. Militaries tend to dislike platforms that are not tightly controllable and predictable, one reason why biological weapons were used so rarely in history. As long as militaries remain uninvolved in geoengineering, SRM is not a prime facie security risk, and the US military will likely steer clear of the issue for at least the near future.