Evil aliens have decided to kill everyone on Earth! Fortunately, they've given you two minutes to save as many as you can. All you have to do is name a country to save everyone in it.
Start by naming any country that France borders. Then name any country that borders any of those countries. Then keep going until there are no more countries left to name.
Not sure why different countries are in the four non-NATO columns. In addition, the definition of "major" is slightly diluted if you include Armenia, Georgia, etc.
NATO itself has four different categories in which other countries can participate in NATO
NATO itself has four different categories in which other countries can participate in NATO
https://www.nato.int/cps/en/natohq/topics_84336.htm
This may make for a more accurate list.
Belarus, Russia, and Afghanistan are of course suspended from any participation.