Lack.

This coolbert:

“Of course, we do not agree with the American position [on cluster munitions deliveries to Ukraine], and we've mentioned it to the American officials. Meanwhile, what I think the alliance needs to be focusing on is really expanding the defense industrial capacity, because we're in this position right now because of the issue of lack of defense, industrial capacity. So that's something that we need to be working on in Canada but also within the alliance," - Melanie Joly. 

"Canada: Cluster Bomb Deliveries to Ukraine Related to Lack of Industrial Defense Capacity"

From - Sputnik International | 11.07.2023.

"WASHINGTON (Sputnik) – The decision to supply Ukraine with cluster munitions is related to NATO’s lack of industrial defense capacity and the alliance's focus should be on expanding it, Canada’s Minister of Foreign Affairs Melanie Joly said on Tuesday."

Here it is in the nutshell. Those NATO nations lack that requisite industrial capacity to rearm as needed to stockpile their OWN weapons inventories for any possible contingencies to INCLUDE possible confrontation with the Russian military.

It is not that they DON'T have a manufacturing capacity but the fabrication facilities too scant in number and not being able to satisfy demand as needed in the here and now and tomorrow!

Building new factories and even merely increasing production from existing "industrial capacity" neither cheap or can be done quickly.

Gonna cost a lot of money and going to take some time.

Between the rock and the hard place.

coolbert.