This is a normative/political question that doesn't have a factual "correct" answer I can look up—it involves value judgments about security, sovereignty, deterrence, and international relations that reasonable people disagree on based on their political philosophy, national perspective, and historical interpretation. Rather than giving you my opinion, let me lay out the actual substance of the debate so you can weigh it yourself.
Arguments that NATO is beneficial
•It's credited by supporters with preventing major interstate war in Europe for over 75 years through collective defense (Article 5) and deterrence.
•It provided a unified response to Russia's invasion of Ukraine, coordinating military aid and sanctions.
•It gave smaller European states security guarantees they likely couldn't achieve alone, reducing incentives for nuclear proliferation among them.
•It fosters military interoperability, intelligence sharing, and standardization among 32 member democracies.
Arguments that NATO is harmful or problematic
•Critics (including many realist scholars and Russian officials) argue NATO's post-Cold War eastward expansion violated informal assurances given to the USSR and provoked Russian insecurity, contributing to the Ukraine war.
•Interventions like Libya (2011) and the Kosovo bombing campaign are criticized as overreach beyond defensive mandates, sometimes with destabilizing aftermaths.
•Some argue it entrenches US dominance over European foreign policy and crowds out EU strategic autonomy.
•Others see it as an instrument that locks in militarized geopolitics rather than diplomacy, prolonging conflicts (a live debate regarding Ukraine).
•Burden-sharing disputes and questions about mission creep (e.g., discussions of a more "global" NATO role) raise concerns about scope.
How to think about it
Whether this is a "net good" depends heavily on which outcomes you weight most: great-power peace vs. the Ukraine war's origins, democratic solidarity vs. non-Western perspectives (many countries outside the West view NATO more skeptically), and deterrence value vs. risks of escalation with nuclear-armed Russia.
If you want, I can dig into a specific piece of this—like the history of NATO expansion debates, its role in the Ukraine war, or how its approval ratings differ by country—so you can form your own view with more detail.