Ukraine should not be admitted to NATO *AT THIS TIME*. For the simple reason it does not currently qualify for membership. Once that changes Membership should be extended.
Russia seems to be suffering from an inferiority complex, as the simple fact that no member of NATO was compelled by the US to join. Russia seems to be harboring a load of butt hurt that it’s Eastern European allies of the Warsaw pact could not leave fast enough once their ability to compel membership in the alliance ended. Putin also seems to be having issues cajoling support from Russia’s current allies.
Its “allies” and Republics in Europe were overrun by the red horde as the German front collapsed, and by the end of the war, England had neither the manpower nor the desire to forcibly wrest control from Stalin, and the US naively trusted him to keep his word and allow free democratic referendums about each country’s ultimate fate. It was Churchill they mistrusted, so did not back him up even diplomatically. But life as a Soviet Republic was all rainbows and unicorns, of course (not!) so unsurprisingly, they all wanted shut of Russia when the Soviet Union finally collapsed under its idiotic system. Especially Ukraine, though also especially Latvia, Lithuania, what was left of Poland, etc.