Before he was known as Suspect No 1 in the Boston Marathon bombing, Tamerlan Tsarnaev was better known as the son of an immigrant family and promising boxer with Olympic aspirations.
Though he won a few local championships, his Olympic dreams fell short. He didn't make it through the Golden Gloves competition. Instead, he seemed to settle into an unremarkable middle-class life, the dream of many immigrants who seek refuge in the US.
He got married, became a family man, found religion and studied accountancy at a local community college.
But like many men whose youthful dreams were not realised, he no doubt carried with him a lingering disappointment.
In his search for purpose, Tsarnaev's religious quest led him to another former boxer and fellow Muslim a world away, "Sheik" Feiz Mohammed, a Sydney-based radical preacher who ran a Liverpool youth centre but also recorded sermons blaming women for their rapes.
The imam also bagged Harry Potter and called for the beheading of the Dutch politician Geert Wilders.
Tsarnaev's YouTube feed had clips of Feiz Mohammed and other radical sermons.
The fact that the rantings of an Australian extremist could carry consequences for a major city in the US truly demonstrates that it is the fluid and instantly accessible radical ideology, more than political grievances, that is the root cause of modern terrorism.
The fact that the Boston bombers hailed from Chechnya, became refugees in Dagestan and later immigrants to the US and were radicalised by a Sydney preacher makes the jihadi ideology a truly global phenomenon.
Tackling the radical ideology that is the motivation for so many to unleash violence must be at the heart of combating the terrorism threat in the future. We must pay attention and combat it wherever it is preached because it is available everywhere and to anyone.
So long as the jihadist ideology remains unchallenged it will remain a threat for open societies and the bane of Muslim communities.
Despite tactical counter-terrorism successes, an unchecked violent jihadist ideology ensures that its radicalising message will continue to appeal to the alienated anywhere and continue to be a matter of concern for governments everywhere.
But there is a deep reluctance on the part of democratic governments to tackle the problem of jihadist ideology. Instead they have focused on disrupting plots and shoring up intelligence efforts against jihadist networks.
All of this is important work but democratic societies also have a critical role to play in articulating open values and discrediting ideologies that go against the national interest.
Many governments fear this effort would be seen as challenging the beliefs of religious or ethnic communities. But challenging violent Islamism isn't a challenge against Islam. Islam isn't Islamism. One is a religion, the other is an ideology.
The Tsarnaev brothers were typical American immigrants until they weren't. It was their exposure to radical jihadist ideology that turned them.
Australia is not immune. Just as the Tsarnaev brothers were influenced by an Australian preacher so too could disaffected youths here be influenced by radicals in other countries.
ASIO has reported that a number of Australian residents have travelled to join the fight in war-torn Syria in recent days.
They will no doubt come back radicalised but in today's world one doesn't have to travel that far.
The jihadist's call is only a click away.