well, NATO’s aim is to contain Russia. Or it WAS
It started after WW2 and was mostly political at first. It became a counter to the Warsaw Pact, led by the USSR and included communist countries. They were reacting to the inclusion of West Germany into NATO. It was a power balance between the two groups.
It built up over the years by back and forth reactions to various things. It does not exist just to oppose Russia, but given the history of its growth, that is likely how Russia views it. Even if the goal is to contain Russia which did not exist in its current state back when NATO began, it fails at that horrible by expanding toward Russia and causing them to feel threatened. The back and forth security reactions are starting all over again.
Remember the USSR and the Warsaw Pact no longer exist. NATO has had to go hunting for new purposes.