"Questioning"- countable or uncountable?

I am quite sure that “questioning” is an uncountable noun. However, in my textbook “questioning” is used as a countable noun. Can you please explain this to me. Thanks in advance.

Most European NATO members have little interest in increasing their military expenditures, but may be forced to in order to maintain the relationship with the U.S (Since the U.S feels it shoulders too much of defensive responsibility in the alliance). This has brought about a questioning of NATO in some countries: Do these nations really want to keep bending to the American’s demands just to preserve NATO?

‘a questioning’ relates to one instance of questioning. (It’s still uncountable in that there is an unspecified number of questions but this questioning took place within one period of time).
‘the questioning’ is also possible.

The very fact that you can talk about ‘a/the questioning’ suggests that it can be countable. Of course in the plural sense it refers to ‘interrogation’. In the example quoted by Quang, the word takes on the idea of raising doubt about something.


Thank you very much, I got it. However, why when i looked up at the Oxford dictionary, it said that this word is only uncountable?