How do I refer to something that happened in the past, but it was recent at that time?

The sentence is something like this: The program was controversial when it was launched in 2017, mostly due to the (then recent) social climate.

the (then recent) social climate.

My first thought:

the then social climate.

I was tempted to overanalyse, but Is it correct to use the word "then" to imply something of the past? offers a comparable example:

The team wanted to show the features of the then new Windows XP.

The accepted answer was that then new is fine so in your case, you might write (without parentheses):

the then recent social climate.

– or, I reckon, simply:

the then social climate.