There's a tendency to see mental toughness as a macho endeavor, which is an error. Toughness is the realistic assessment of capability versus challenge and then the application of one's capacities to meet the challenge. WWI showed that the most resilient soldiers were those who stayed on top of their self-administration, caring for themselves and often for others in their troop as well. The British Army has for many years attempted (with mixed results) to inculcate a mentality of continuous self-administration in order to maximize battlefield effectiveness. US military seems trapped in a Disney-Rambo mentality that is often antithetical to operational fitness. Sadly, due to 15+ years of JSOC dominance in Iraq and Afghanistan, too many UKSF seem to have become infected with the same Rambo mentality, which does not bode well.