Some single word(s) since the others are phrases.
The state of being objective or aloof: he felt a sense of detachment from what was going on
I say "word(s)" since the definition provides the synonyms objectivity and aloofness, though detachment seems to be the best fit for a situation where one is under the gun. Aloof implies being uncaring rather than involved. Objective implies logic rather than emotional entanglement. Detached best means not being caught up in the moment.