This is a question that calls for your own reasoned judgment rather than a factual lookup—it's a normative/political question where reasonable, informed people disagree based on differing values, priorities, and interpretations of history. I don't think it's my place to hand down a verdict on this; instead, let me lay out the actual substance so you can weigh it yourself.
The case that NATO has been beneficial:
•Deterrence and stability in Europe: NATO's collective defense principle (Article 5) is widely credited with helping prevent major interstate war in Western Europe since 1949, and arguably extended that peace eastward after the Cold War.
•Crisis response and counter-terrorism: NATO led stabilization missions (e.g., in the Balkans in the 1990s, which helped end ethnic wars) and invoked Article 5 after 9/11 in support of the US.
•Supporting Ukraine's defense without direct NATO combat involvement: Many argue NATO's coordination of military aid to Ukraine since 2022 has helped a country resist invasion without triggering a direct NATO-Russia war.
•Democratic alliance structure: It binds together democracies with shared decision-making, arguably making aggressive unilateral action by members less likely.
The case for skepticism or criticism:
•Expansion and Russian security concerns: Some scholars (realists like John Mearsheimer) argue NATO's post-Cold War eastward expansion provoked Russia and contributed to instability, including the Ukraine war—though this is contested by others who blame Russian imperialism itself.
•Out-of-area interventions: NATO's role in Libya (2011) and Afghanistan led to outcomes many consider failures—Libya descended into prolonged chaos, and Afghanistan ended in Taliban return to power after 20 years.
•Burden-sharing and democratic accountability tensions: Critics note inconsistent member commitment to spending targets, and debates about whether decisions are driven more by member-state interests than collective good.
•Nuclear posture and arms dynamics: Some peace-oriented critics argue military alliances like NATO perpetuate militarization and arms races rather than resolving underlying conflicts.
My honest take: Whether you view NATO as a "force for good" depends heavily on which outcomes you weight most (deterred wars in Europe vs. interventions gone wrong), your view of Russian vs. Western responsibility for post-Cold War tensions, and your general stance on military alliances as tools of peace versus engines of conflict. I'd encourage you to look at specific episodes (the Balkans, Libya, Afghanistan, Ukraine) individually rather than rendering one verdict on the whole 75-year institution, since its track record is genuinely mixed depending on the lens.
Is there a specific aspect—like a particular conflict, NATO's role in Ukraine, or expansion policy—you'd like to dig into further?