That isn’t the only response. There are a lot of things NATO can do without committing ground forces: - NATO could ensure a supply train for material coming fr

That isn’t the only response. There are a lot of things NATO can do without committing ground forces: - NATO could ensure a supply train for material coming from Poland and Romania: all Ukrainian forces need to do is hold a corridor from Poland/Romania to Lviv. - NATO could share intelligence and strategic advice to aid the Ukrainian forces’ ability to respond (I believe this is already happening) - if the war bogs down while Russian troops hold onto say a large area east of Kyiv, then NATO could use the “impregnable state border” to provide troop training and re-supply from inside the Polish border, or in an area just over the border in Ukraine. - NATO could train Ukrainian pilots in Poland, and allow Ukrainian planes to be based out of a NATO air field (and could even supply those pilots with NATO planes, missiles, fuel, etc), similar to how Germany allowed the US to use bases on German soil to launch attacks on Iraq. The last option seems unlikely (it’s probably close enough to joining in the fight with your own personnel that Putin would respond accordingly). But it is still something that could be done, would help Ukraine wage war, and wouldn’t technically involve NATO troops fighting within Ukraine.