Nato to expand "high readiness" troops from to 300K from 40K
High readiness means fully equipped and ready to fly anywhere on a moments notice. Many troops will be pre positioned and equipment stored close to Nato's eastern side. The Baltics are considered especially vulnerable to Russian aggression.
The invasion of Ukraine, and the way in which Russia has prosecuted it's war by purposely killing and terrorizing civilians has been a huge encouragement for all of Europe to join together in self defence.
300,000 troops all equipped with the most modern aircraft, armor, etc. would more than likely be enough to deter Russia from further invasions.