Nothing as it would just shoot it down like everything else they shoot towards our ships…
The Phalanx is a ships Last resort close range weapons system.
If it makes it that far…
The Phalanx CIWS (SEE-wiz) is an automated gun-based close-in weapon system to defend military watercraft automatically against incoming threats such as aircraft, missiles, and small boats. It was designed and manufactured by the General Dynamics Corporation, Pomona Division,[3] later a part of Raytheon. Consisting of a radar-guided 20 mm (0.8 in) Vulcan cannon mounted on a swiveling base
