what methods the cia,fbi,or specialists soldiers use to train the mind in a difficult situation?

Question

it means ex:the snipers are in the same position by hours instead that they switch sometimes,the undercovers use to work by weeks in the middle of stressful situations etc...i hope you got the idea.

Answer 1

Dicipline and conserving energy for snipers, but say during torchure the idea is to concentrate on a more pleasant situation, try to remember the feel of details during physical duress.

Answer 2

?
Are you asking how to withstand torture?

You learn to disassociate yourself from the pain, and convert it to repressed anger at the one doing it.

If you get the chance, retribution.