That way, there's a clear line for what NATO will and won't do that Russia can understand. If attacks escalate it will be Russia that escalated every time. If Russia feels it's threatened, all they have to do is stop the attacks and NATO will stop. If Russia is going to nuclear warfare over not being able to unevenly harass NATO, because we can't read Putin and the oligarchs' minds, and what objective measure would allow that but not allow Russia to go nuclear warfare over not enslaving all of NATO, or claiming they can/others can't do everything not written unambiguously in a treaty (which would extend to new technologies like partitioning the solar system that we couldn't have thought ahead-of-time)?
But I'm no diplomat, so maybe I'm wrong and my idea would be catastrophic.