What is the primary weapons system used by aircraft carriers for defense?

The primary weapons system used by aircraft carriers for defense is the Phalanx Close-In Weapon System (CIWS). This system is designed specifically for short-range defense against incoming threats, such as missiles and enemy aircraft. The Phalanx employs a rapid-fire gun, typically a 20mm M61 Vulcan cannon, which can engage targets at a very close distance with a high rate of fire. This capability is crucial for aircraft carriers, as they often operate in contested environments where they may face various threats.

While other systems listed, such as the Standard Missile 6 and the Sea Sparrow, are effective in their roles, they primarily serve as medium to long-range defense against aerial threats and anti-ship missiles. The Tomahawk Missile, on the other hand, is primarily an offensive weapon designed for long-range strike missions rather than defense. Therefore, the Phalanx CIWS stands out as the dedicated short-range defense system tailored to protect aircraft carriers against immediate threats, making it the primary choice for defense in this context.