No matter how wretched and perverted the nature of a terrorist attack, there's always a movement of people hellbound to take agency away from the perpetrators and lay blame at the feet of their victims.

Manchester will be no different. It doesn't matter how many people were killed. Or how many more got wounded or traumatised. Because the victims, as they should, never take the central stage in the guilt-ridden, self-hatred narrative of the apologist crowd.

We will hear theories about how marginalised, disadvantaged individuals are "made" to blow themselves up among groups of young people. How our bombs and drones are "triggering" violent responses on our soil against imperialist aggression in Islamic countries. How we are "inviting" blowback against Muslims for wanting to address the dangers of radical Islam.

But our concern, first and foremost, must be with the victims. They are the ones lying dead in a morgue, unable to ever embrace their parents, wives, husbands, brothers, sisters, children and friends again. They are the ones leaving behind irreplaceable emptiness and broken hearts. Nothing, absolutely, nothing is worse than that.

18-year-old girl Georgina Callander was identified as the first victim. Eight-year-old Saffie Rose Roussos from Leyland has been named as the second victim of this horrific attack.

Make no mistake. We are collecting the body parts of our children, murdered in the middle of Manchester, because of everything we do right in life.

Their killer hit a pop concert. He wanted to kill children. Our children. They were murdered in cold blood because they were happy. Because they loved music. Because they enjoyed the simplest pleasures in life. Period.

Georgina Callander
Georgina Callander, 18, and eight-year-old Saffie Rose Roussos Twitter/Facebook

In short, because they celebrated life itself. The very thing death-worshipping, braindead jihadists despise more than anything.

That's what we're up against.

Islamic State has claimed responsibility for the suicide bombing. Western foreign policy is not the catalyst of their barbarism. Our actions don't explain, let alone justify, why terrorists kill children at a pop concert. Why they drive cars into pedestrians and slit someone's throat. Or why they enslave and murder ethnic and religious minorities. No air raid over Raqqa or a drone strike in Pakistan makes the slightest bit of difference to the murderous ideology we are up against.

What connects their unspeakable litany of crimes – from Baghdad to Paris, Manchester and Jerusalem, Jakarta and Stockholm – is their undisguised contempt for life grounded in the poisonous ideology of Islamism.

It is the same Islamist ideology in which name the Taliban slaughters girls for dancing in the streets of Kandahar. And the same perversion that makes Islamic State and other jihadist groups ban music by sword wherever they go.

Once again, the terrorists and their sympathisers will justify their acts of barbarism under the false premise of challenging the West's amoral and unethical foreign policy. And yet again too many will too readily buy into their narrative, too terrified of admitting the truth about the threat we face.

Should you, in the wake of the horrific terrorist attack in Manchester, encounter an apologist today, make sure to mince no words. Tell him to his face what you think of him and his sick, twisted way of blame deflection.

Tell him that you are proud of who we are. How we live. What we stand for, embrace and celebrate. Enough of the excuses, dodging responsibility, and false equivalences.

Julie Lenarz is the Executive Director of the Human Security Centre and a Senior Fellow at The Israel Project. She tweets at @MsJulieLenarz