North Korea is powerless to prevent a U.S. strike on its nuclear program, but retaliation is well within its means. The significant military capability that North Korea has built up against South Korea is not advanced by Western standards, but there are practical ways Pyongyang could respond to aggression. The North Korean military's most powerful tool is artillery. It cannot level Seoul as some reports have claimed, but it could do significant damage. Pyongyang risks deteriorating its forces by exposing them to return fire, however, which significantly restricts their use. Less conventional methods of retaliation, such as sabotage or cyber warfare, are less risky but also limit the shock that North Korea would desire. After a strike, North Korea's most immediate and expected method of retaliation would center around conventional artillery. Many of the North's indirect fire systems are already located on or near the border with South Korea.