This paper considers the impact of Stuxnet on cyber-attacks and cyber-defense. It first reviews trends in cyber-weapons and how Stuxnet fits into these trends. Because Stuxnet targeted an industrial control system in order to wreak physical damage, the focus is on weapons that target systems of that type and produce physical effects. The paper then examines the impact of Stuxnet on various domains of action where cyber-attacks play a role, including state-level conflict, terrorism, activism, crime, and pranks. For each domain, it considers the potential for new types of cyber-attacks, especially attacks against industrial control systems, and whether such attacks would be consistent with other trends in the domain. Finally, the paper considers the impact of Stuxnet on cyber-defense.