The following is the Jan. 18, 2023, Congressional Research Service In Focus report, PATRIOT Air and Missile Defense System for Ukraine..
From the report:
The PATRIOT air and missile defense (AMD) system is an integral component of U.S. air and missile defense. The system and its interceptors are both expensive and limited in supply. On December 21, 2022, the Department of Defense (DOD) announced the United States would provide a PATRIOT battery to Ukraine as part of a larger $1.85 billion security assistance package. The provision of PATRIOT units now, and whether or not the United States may transfer additional PATRIOT units to Ukraine in the future, present issues that Congress will face in both its legislative and oversight roles.
What Is the PATRIOT System?
PATRIOT is an acronym for “Phased Array Tracking Radar to Intercept on Target.”
The U.S. Army Aviation and Missile Life Cycle Management Command (AMCOM) notes
The PATRIOT is the U.S. Army’s most advanced air defense system. Capable of defeating both high performance aircraft and tactical ballistic missiles, it is the only operational [U.S.] air defense system that can shoot down attacking missiles. A PATRIOT battery (the basic firing unit) consists of about 90 soldiers, but three soldiers in the engagement control station are the only personnel required to operate the battery in combat.
Raytheon Technologies manufactures PATRIOT radar and ground systems, and Lockheed Martin manufactures the interceptor missiles.
DOD’s December 21, 2022, Ukraine Security Assistance Announcement
DOD’s December 21, 2022, announcement appears to represent a change in the Biden Administration’s position on the supply of PATRIOT units to Ukraine. Since Russia’s February 2022 invasion, the Ukraine government repeatedly has asked the United States to supply PATRIOT systems. The United States to date has provided other, less capable AMD systems. According to a DOD news article, “Ukraine Getting Patriot Battery, Other Defense Weapons,” the United States will transfer a PATRIOT battery under the provisions of Presidential Drawdown Authority (PDA), meaning PATRIOT battery systems, equipment, and associated interceptors could be taken from Army units/stocks (22 U.S.C. §2318(a)(1)). DOD further noted
PATRIOT is one of the world’s most advanced air defense systems, and it will give Ukraine a critical long-range capability to defend its airspace. It is capable of intercepting cruise missiles, ballistic missiles and aircraft … Our goal is to help Ukraine strengthen a layered integrated approach to air defense. PATRIOT will complement a range of medium and short-range air defense capabilities [Stinger and National Advanced Surface-to-Air Missile System (NASAMS)] that we have provided and the allies have provided in prior donation packages … PATRIOT is a sophisticated air defense system so training will be required and will take some time.
Download the document here.