A big part of WWI is that the web of treaties and alliances were all secret, as in classified information by each country.
NATO is not a secret. The membership roster and terms and conditions are known to all, including potential adversaries like Mr. Putin. This has a major effect on stabilizing international relations because nobody has to guess what NATO would do.
Despite his rhetoric, we know that Putin understands how NATO works, because he has been pulling materiel out of Kaliningrad. This leaves the Russian exclave extremely vulnerable to an invasion from NATO territory. But Putin is not worried about that, probably because he actually trusts NATO to follow the NATO charter.