"Essentially" is carrying a lot of weight in that sentence. NATO _personnel_ (not necessarily soldiers, but officers and staff) have been active in Ukraine since 2014-15.
Well why don't you estimate the number and compare it to the total size of _personnel_ so people could judge if that number is indeed essentially zero? (spoiler alert, it is)
“What kind of war?”
“Russia is fighting NATO.”
“Are you serious?”
“Yes, yes! Russia is fighting NATO.”
“So how’s it going?”
“Well, 70,000 Russian soldiers are dead. The missile stockpile has almost been depleted. A lot of equipment is damaged, blown up.”
“And what about NATO?”
“What about NATO? NATO hasn’t even arrived yet.”