Moscow is not happy.
THAAD Missile Defense Systems Are Coming to Russia's Doorstep
The U.S. Army has deployed to Romania one of its seven Terminal High-Altitude Area-Defense missile-interceptor batteries. The deployment coincides with a shut-down of the U.S. Aegis Ashore missile-defense site, also in Romania, for a scheduled upgrade.
The THAAD battery on May 17, 2019 began setting up its equipment within sight of the Aegis Ashore missile-defense site. The U.S. Army and the U.S. Defense Department separately posted, then quickly deleted, at least one photo of the battery preparing for duty. Some websites have preserved the photo.
The THAAD deployment is controversial. The system, in theory, possesses some of the same capabilities that Aegis Ashore does and could help to fill the gap left by the Aegis system’s temporary suspension.
But THAAD also has antagonized the Russian government, just like Aegis Ashore has done. Russia "can’t understand what tasks the Aegis Ashore system will accomplish in the missile defense area,” Russian deputy foreign minister Sergei Ryabkov in late April 2019 said.
The Pentagon and NATO repeatedly have tried to explain their reasoning for deploying THAAD. “At the request of NATO, the secretary of defense will deploy a U.S. Army Terminal High Altitude Area Defense system to Romania this summer in support of NATO ballistic-missile defense,” U.S. European Command in early April 2019 announced.