It is perfectly obvious that the missile defence bases [in Romania and Poland] are purposefully placed on the Western borders of the Russian Federation and target no country other than Russia.
The defence base in Romania has MK-41-start bases, which can pretty easily be used for the launch of heavy cruise missiles of the Tomahawk-class. These are cruise missiles with a medium range-reach which immediately breach the INF-Treaty from the year 1987.
According to the U.S. Naval Forces Europe-Africa (2016): the Aegis Ashore Missile Defence System is part of the European Phased Adapted Approach, designed to protect European NATO allies, and U.S. deployed forces in the region, against current and emerging ballistic threats from the Middle East. U.S. Naval Forces ruled out the possibility of targeting the Russian Federation with the "Aegis Ashore" system.
The Romanian Defence Minister Teodor Melescanu also reiterated on February 7 2019 that "Aegis Ashore" was a strictly defensive system.
The missile defence stations, also known as "Aegis Ashore", are technically based on the Mk41 launchers (in accordance with the INF Treaty) used on ships, which can also launch cruise missiles. According to the US government they are modified that they can only launch defence missiles and not offensive ground-to-ground missiles, concludes the Research Services of the German Bundestag in 2018 (P.2, in German).