The answers given explained the thinking at the time they were given - for myself, my views have changed significantly over the last 18 months.
Personally * teuchter I think that if the NATO summit in Vilnius this week doesn't see a clear, *relatively quick pathway for Ukraine to join NATO thrashed out (not next week, or next month, but next year perhaps), then you might start to see individual member states looking at what they might do on an individual level - the most obvious one being Poland.
If Poland, already one of the most capable land powers on Europe, and one of the most hawkish on Ukraine, decided to use it's military power to create safe areas in Ukraine (Surface to Air missile batteries in Kyiv, Lviv, Odessa etc.. and fighters in the sky to the west of the Dnipro-Kharkiv line), would Russia seek to attack /shoot them down, or would they effectively accept that western Ukraine was now out of bounds, despite giving the Ukrainian military much respite and allowing it to concentrate it's forces
If Poland intervenes, would Russia attack Poland (where I sit, typing this out..) with missiles or air strikes how would NATO respond to air attacks on a NATO member state?