British born Salman Abedi was one of them. His father had been a member, in the 1980s and 90s, of the (proto-al Qaeda) Libyan Islamic Fighting Group, a fanatical sectarian murder gang that brought terrorism to Libya and was sheltered and funded by the UK.
Salman was still a kid when Cameron waged his war of terror in Libya. Yet somehow this kid ended up there fighting inbetween breaks from school in the UK.
He can only have got there the same way his dad and his mates did. On British transport flights courtesy of MI6, carrying British supplied guns, paid for by British money, under the cover of the bombers of the RAF.
David Cameron and William Hague stood up in Parliament and bragged about their role in arming these terror gangs that destroyed Libya, butchered Muammar Gaddafi, sent half its population into refugee exile in neighbouring Tunisia, and brought slave markets, chaos, ethnic cleansing and still ongoing civil war to those that remained.
As Home Secretary and in regular contact with the UK's intelligence services through the Joint Intelligence Committees, Theresa May would have been central to greenlighting the recruitment of terrorists and sending them to Libya and elsewhere. And, crucially, in her role as boss of the UK Border Agency, in giving them entry to live in the UK and the British passports that allowed them to travel across borders unhindered.
That one of those terrorists, taking the training and contacts he had been granted only by the collusion of the British government's work in Libya, has come home and used his skills to bring the Libyan "revolution" back to the UK, should be hammered home by the opposition.
That 22 innocent people, many of them children, died in Manchester is intrinsically linked to the many thousands more innocents that died in Libya, and are still dying today, often washing up on Europe's beaches. It is a scandal of monumental proportions and needs to be brought fully to public attention
(Of course, it is pertinent to remember that large sections of the English Left fully supported this "revolution" and the terror and destruction it wrought, and still do support it as it continues in Syria)
To imagine that Salman Abedi, who was sixteen years old and still at school when he was first sent to fight in Libya in 2011, and was a frequent traveller to what is left of that country to engage in further acts of terrorism at will, up until just a few weeks ago, could do so without the full knowledge of the British intelligence services is beyond credibility.
Indeed they admit Salman Abedi was "known" to them, in actual fact he has to have been in direct contact with them. We also know that British intelligence and special forces are on the ground even now in Libya continuing to sow chaos and destruction, just as Salman Abedi and his father and brother were.
From Ireland to Afghanistan, to Libya and Syria, collusion between British intelligence services and the most ideologically reactionary and sectarian terrorist death squads has been standard operating procedure for British counter insurgency policy against states and movements it wished to overthrow for at least half a century or more.
There are so many questions that absolutely must be raised and demanded to be answered. Jeremy Corbyn should be calling for a full inquiry into what was known and by who. Who greenlighted Abedi, as a child, being recruited to fight in Libya? In fact we know the buck stops with Cameron, Hague and Theresa May. Now is the time to bring them to account.