Achilles heel of US army

The US army has miserably failed to acquit itself with aplomb in Afghanistan to date and there are doomladen forecasts about the future also, because its culture resonates with features which, in the past also, have made big powers to get disposed of by inferior enemies in the guerrilla wars. Guerrilla wars, which are for the most part asymmetric conflicts, do not hinge upon the expeditious operation of complex mechanical devices, highly coherent logistical system etc for success.
The success in these wars pivots on the strength of emotions, superiority of will and the tolerance for heavy casualties. From the Teutoberg Forest, to the long march, to the Tet offensive, adversaries who were unambiguously and markedly under par in weapons, military and organisation mopped the floor with superior armies and managed to persevere to ultimately notch up victories on the back of the Rolls-Royce of will, disposition to accept ginormous costs and belief in 'death or victory'.
The most tragic fact with American military is that there is a partiality and fondness for minimising casualties. "We must expend steel and fire, not men," General Van Fleet, 8th Army, 1951. A cogent Strategic Studies Institute (SSI) study has explicated that casualties are chiefly a perceptual issue with the core leaders of US military strategic and political culture. True to form, America is unable or indisposed to accept high casualties and costs in Afghanistan. Equally important is the absence of will and lack of motivation on the behalf of its soldiers to run the risk of death. The case is quite the obverse with Al-Qaeda.