Answer:
Yes.
Step-by-step explanation:
NATO is an alliance between United States, France, Canada the United Kingdom, and eight other different European countries. If one of these countries get attacked, then all the other countries who are a part of the NATO alliance will attack the attacker in result. Ukraine isn't apart of NATO, if it were before the invasion from Russia, it would have started a world war where Russia would have been easily destroyed (not mentioning Russia's own alliances) because even though Russia has a strong military presence, so does the United States along with eleven other countries who are a part of this alliance. Alliances such as NATO are very important because it insures if you were to be attacked you would have many countries armies on your side to help defend you. So, the answer would be "yes," there is still a need for alliances such as NATO.
Hope this helps.