Here's a simple response.
Ukraine had no interest in joining NATO.
Russia has invaded Ukraine.
Ukraine now has an interest in joining NATO.
Oh baloney!....just as in everything else about Ukraine they are hot then cold on everything, and that includes Nato...all pending on what elections are happening at the moment and which Oligarchs have what influence and where.
From the moment of the 1991 collapse of the USSR Nato has ‘relentlessly’ pursued a strategy of encircling Russia and still is doing so as it entices with carrots other countries not yet members...(check the maps, any maps on Nato Expansion) ..it's brought 12 countries into central Europe, all formerly allied with Moscow, into the NATO alliance with Ukraine being the “gold”. Putin finally drew a line at Ukraine from his perspective.
Putin's biggest beef is he's not about ready to let the US/Nato put Military bases in Ukraine, or for that matter any of the former Soviet Countries without some serious backlash. Both the Orange and the Maidan revolutions agreed to placing such as condition of accepting their money.
Ukraine has always been on the table for Nato membership...and it always will be...it's in the EU expansion plans......remaining neutral will only be until the population is reconfigured which we see happening now.
The Western Ukraine is all for Nato Memebrship.....they just have to spread the population around...(free housing in the east now for westerners) also riding much of the East of the Russian population.. either by shelling or by moving out as refugees. This too we see happening.
Eu/Nato knew well Ukraine would be a tough take...and that Putin wouldn't just stand by....they also knew their was resistence by some of the population enough to slow it down from joining Nato. But you can bet with certainty the plan is for Ukraine's full membership with Nato when all is said and done...and it isn't close yet.