[nowandlater]

For the US, I highly recommend the Nuclear Posture Review, which is compiled by and details the current administration's policy as it relates to its nuclear stockpile and strategic purpose.

The last one, 2018: https://media.defense.gov/2018/Feb/02/2001872886/-1/-1/1/201...

https://en.wikipedia.org/wiki/Nuclear_Posture_Review