Key point: Washington has wanted to expand NATO's anti-missile capabilities for a while now.

A key NATO missile-defense site in Romania on Aug. 9, 2019 completed a three-month upgrade process that had forced operators to take the system offline.

To fill the resulting gap in coverage, the U.S. Army in May 2019 deployed to Romania one of its seven Terminal High-Altitude Area-Defense missile-interceptor batteries.

The THAAD deployment was controversial.

The THAAD system set up within sight of the Aegis Ashore site in Romania. The Army and the U.S. Defense Department separately posted, then quickly deleted, at least one photo of the battery preparing for duty. Some websites preserved the photo.

THAAD 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 said in late April 2019.

The Pentagon and NATO repeatedly 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 announced in early April 2019.

“The THAAD, from the 69th Air Defense Artillery Brigade, 32nd Army Air and Missile Defense Command stationed at Fort Hood, Texas, will integrate into the existing NATO BMD architecture during a limited period of scheduled maintenance and updates on the Aegis Ashore missile-defense system in Romania this summer.”

As of early 2019 the Army had acquired around 200 THAAD rockets for its seven batteries and roughly 40 launchers. The U.S. Missile Defense Agency on its website describes THAAD as a “land-based element capable of shooting down a ballistic missile both inside and just outside the atmosphere.”

The U.S. Army mans THAAD batteries on the island of Guam as well as in South Korea. The Army in March 2019 deployed a THAAD battery to Israel.

Aegis Ashore is a land-based version of the U.S. Navy’s SM-3 missile-interceptor. The Missile Defense Agency by way of NATO operates Aegis Ashore sites in Poland and Romania. The sites help to defend Europe and the United States from limited missile strikes by a Middle East power such as Iran.

But U.S. missile defenses for decades have been controversial in Russia. Moscow views American BMD systems as a threat to the global balance of power, as they in theory could render ineffective Russia’s own nuclear-tipped rockets. In fact, most U.S. missile-defenses lack the speed, range and accuracy to intercept an intercontinental ballistic missile.

Only the United States’s Ground-Based Midcourse Defense systems in Alaska and California, both of which exist to intercept North Korean rockets, in controlled tests have proved to be capable of hitting some ICBM-class weapons.

Many Russians also believe, wrongly, that Aegis Ashore has a ground-to-ground capability and could function as a surprise first-strike weapon. Aegis Ashores "play[s] to a very specific Russian fear," said Jeffrey Lewis, a nuclear expert at the Middlebury Institute of International Studies at Monterey.

Lewis said many Russians believe the United States has planned for years to secretly arm its missile-defense installations in Poland and Romania with nuclear weapons, transforming defensive weapons into what Lewis describes as a "covert" strike force whose true mission is to launch a surprise atomic attack on Moscow in order to "decapitate" the Russian government.

"It's insane but I swear they 100-percent believe this," Lewis said of the Russians.

NATO stressed that neither Aegis Ashore nor THAAD poses a danger to Russia. “The THAAD unit will be under NATO operational control and the full political control of the North Atlantic Council,” the alliance stated  “It will only remain operational until the Aegis Ashore Romania site is back online.”

Three months later, Aegis Ashore was done updating. “The THAAD system will now be redeployed as planned,” NATO announced on Aug. 9, 2019.

David Axe serves as Defense Editor of the National Interest. He is the author of the graphic novels  War Fix, War Is Boring and Machete Squad. This first appeared in August 2019.

Image: DVIDShub.