I feel like this is a topic that, given @sb 's logic, can be debated one way or the other. In his defense, looking at WW1 and the idea of 'entangling alliances' giving way to all out war, you can argue that having larger military alliances increases the chance of war (while also minimizing through deterrence).

There is a... sweet spot, between deterrence being effective, and literally taking so many members that war becomes likely/inevitable whether through accident or otherwise.

I actually disagree with you on this. Extending NATO Article 5 protections to an ever-expanding list of countries is shockingly dangerous. Smaller countries feel secure that they have the protection of the US nuclear umbrella, and tend to take rash actions.

Here's a recent example where Lithuania began blocking the arrival of goods from the Russian mainland to the Russian territory of Kaliningrad (https://www.express.co.uk/news/politics/1628780/what-is-happening-between-lithuania-russia-evg)

This kind of tension can easily escalate into a hot war. Lithuania would never dare to block Russian goods if they didn't assume they would have NATO protections.