Unwarranted.  The interceptors throw <15 kg unarmed kill vehicles and do not have land strike guidance packages.  Only a small number in fixed launchers -- easily countable from the surveillance assets -- will be stationed in Europe.  Russia can launch long range ballistic missiles from its submarines.  It can launch them from fixed and mobile land sites over the North Pole and Pacific Ocean.  Russian fears about the U.S. system negating Russian retaliatory capability are unwarranted, however, their fears concerning how the West is attempting to marginalize Russia are completely warranted.  Without nukes or oil, Russia is a big fat nothing in its current state and the Russian citizenry is highly unlikely to ever become ambitious enough to change this.

 

v^2

If it's good enough to take down ballistic missiles, then it can also take down planes. And it comes with a nifty radar, that I suspect the system might be able to track plane movements deep into Russian territory. Not to mention that some radars can make quite effective jammers with respect to electronic warfare.

 

Actually, the current missile design probably cannot take down plane without a lot of luck.  The missile is optimized for an exo-atmospheric interception and lacks the on-board sensors and control surfaces for the level of in-atmosphere maneuver required for an effective anti-aircraft missile.  The last stage is little more than a set of sensor pack and some maneuver thrusters, the proverbial brick has better aerodynamics, and would probably shred itself if deployed in atmosphere.

Due to the curve of the Earth, a radar (especially one on the ground) can only see so far. Russia doesn't exactly border either Poland (except that enclave) or Czechia, there's still either Byelorussia or the Ukraine inbetween.

Besides, NATO already has heaps of AWACS which are much better at that in case of war.

The Ukraine also offered NATO it's use of it's own radars, which are much further East, although these are obsolete.

This ABM-system is a defensive weapon and is not a threat to Russia.

Not to mention Russia is now threatening with responding by placing offensive weapons in it's furthest West province. 

 

As an earlier poster already remarked, it's a fixed emplacement. That would make it vulnerable if it was meant for a conventional WWIII situation.

Taking down airplanes would be done much better with SAMs, which can be purchased on the world market from either the Ukraine, Israël, UK, France or the USA. SAM-systems also come on trucks/tracks so are highly mobile.