Because it’s the right thing to do. Because they’re getting invaded by a fascist dictatorship.

Ask yourself what the alternative is and what a successful outcome for Russia will enable for Putin! Then ask yourself what that means for Europe. Finally ask yourself what upheaval of a European market will do to an American economy and America’s ability to make its influence felt across the world.

Helping Ukraine is far cheaper.

why is nato helping a country fight russia?

It’s not ‘helping’, it’s using generations of Ukrainian men for draining Russian resources and manpower. US provoked this war and they want to prolong it as much as possible because it drains Russia and the EU.

I think its definitely too early to say whether or not any particular element of either Russia or Ukraine’s strategy in the war has been ‘viable’ at this point in time. The ultimate long-term effects of either side’s major strategic decisions are probably difficult to understand right now even for the ones who have been making them, let alone for outside observers such as ourselves.

We can at least acknowledge that Bakhmut was the culminating point of Russian offensive operations in the Donbas. Would it have been the culminating point of their offensive if Ukrainians didn’t defend it so fiercely? Who can say. Both Russian and Ukrainian forces were heavily attrited in the battle there - will this benefit Russia or Ukraine more? Who can say. There are ‘conventional wisdom’ answers to both of these questions, but the nature of the fog of war is such that even small, seemingly unrelated developments can drastically alter the valence of what was previously established as strategically advantageous for one side or vice versa.

Even when institutions dedicated to the study of warfare attempt to analyze utilized strategy X versus counterfactual strategy Y from some episode of military history, the debates are often unending. So can’t you see how cringe it is to claim as a layman that it should’ve been obvious to a given commander (and at runtime, too, despite the fact that you’re making the criticism with the benefit of hindsight) that strategy Z would have been clearly superior to whatever it was they thought was best, back then?