The events of the moment - the murder of a young soldier in the street by two extremists, the parallel violence from British far-right and the riots in Sweden - all illustrate the age-old dilemma of young men with too much time on their hands.
Directionless boredom creates a vacuum that is easily filled with the rhetoric of bitterness and hatred. Fuelled by restless, testosterone-laden energy harnessed to some purpose, no matter how senseless or misguided, they can go off like a rocket, damaging all in their wake.
All the talk of tackling terrorism, tracking the apprentices of terror and monitoring the movement of extremist organisations will not prevent attacks of either the mob or individual. If there is no direction that leads to meaningful employment, education or training, then the way is open for the "lost" to be "found" by ideologies and beliefs that serve to give them some distinction no matter how dubious the source.
High levels of youth unemployment are the mark of so many countries and, for many, it is the young men that make up a big proportion of the disaffected.
Tectonic shifts in the social order have brought changes that have left young men on the margins. The loss of blue collar manufacturing jobs, replaced by a need for highly-skilled workers, the opportunities for higher education that have been seized by women wanting employment equity, combined with the failure of males to see the possibilities in education have pushed young males into a corner.