The will to fight.

As the Taliban rapidly crushed US-backed Afghan forces, many politicians, pundits, and military leaders expressed surprise at having overestimated an ally’s will to fight and underestimated the enemy’s. Similarly in 2014, after the Islamic State (ISIS) routed US-backed Iraqi forces, President Obama endorsed the intelligence assessment that “predicting the will to fight…is an imponderable.” That attitude reflects political and military leaders’ continual discounting of research, supported and known by many of those leaders, on the importance of sacred values and spiritual strength to the will to fight. It may remain “imponderable”—and attendant security challenges seemingly intractable—so long as it continues to be viewed through a narrow lens of instrumental, utilitarian rationality.