At the same time, an anti-aircraft unit equipped with Type 03 medium-range surface-to-air missiles, previously based in Nagasaki prefecture, was also relocated there.
陸上自衛隊宮古島駐屯地編成完結! pic.twitter.com/LCEesSGC8t
— 陸上自衛隊 宮古島駐屯地 (@camp_miyakojima) April 5, 2020
People’s Liberation Army Navy (PLAN) vessels and aircraft (Xian H-6 bombers, Shaanxi Y-8 electronic warfare aircraft etc…) regularly transit through the Miyako Strait, located between the islands of Miyakojima and Okinawa.

The Miyako Strait is about 135 nautical miles wide. The Type 12 deployed in Miyakojima have a range of around 108 nautical miles. A version with double range is under consideration.
While entirely included in the Exclusive Economic Zone of Japan safe passage through the strait is authorized for merchant vessel and warships in peacetime.
A2/AD in First Island Chain

Japan has been stepping up its Anti-Access / Area Denial (A2/AD) solutions, fielding a network of anti-ship and electronic warfare systems in its Southern islands (the so-called “first island chain”). The newly created amphibious bridage of the Japan Ground Self-Defense Force (JGSDF) will also be in charge of defending these islands.
The JGSDF and the US Army conducted their first ever combined anti-ship drills in Japan last year, as part of the annual Orient Shield exercise. The exercise involved both HIMARS and Type 12 SSM. At RIMPAC 2018 exercise, the American HIMARS system conducted an anti-ship attack exercise in cooperation with the Japanese Type 12 SSM.
The US Marine Corps is also about to gain anti-ship capability: Under the Navy-Marine Expeditionary Ship Interdiction System (NMSIS), the US Marine Corps is looking at adding more punch to the US Navy’s anti-ship capabilities with the procurement of (land based) coastal defense batteries. Three missiles are currently under consideration: Lockheed Martin’s newLong-Range Anti-Ship Missile (LRASM), Raytheon/Kongsberg Naval Strike Missile, and Boeing’s Harpoon. Companies submitted their final proposal in December 2018. The USMC is considering three wheeled platforms to launch the future anti-ship missiles, which are the M142 HIMARS, as well as the Medium Tactical Vehicle Replacement (MTVR) truck and the Logistic Vehicle System Replacement (LVSR) from Oshkosh Defense. According to US sources, the USMC plans to test prototypes in the spring of 2020.
In May 2019, it was announced that the USMC will be procuring Naval Strike Missiles from Raytheon. Naval News understands that the USMC will likely integrate the NSM on unmanned JLTV ROGUE Fires vehicles:
