Maj Andrew Fox, of the Henry Jackson Society, said those people who tended to be radicalised were more likely to be second or third generation immigrants to the UK but warned it was ‘impossible to quantify’ if recent immigrants were coming to the UK for ‘malign reasons’.

Speaking on GB News Andrew Fox said: “I think it’s more the case that [terrorists] are looking to cause the most terror they can. Terrorism has always been about making fear, about making people terrified to leave their homes and trying to achieve some sort of political end by terrorising the population.

“And it stands to reason that the targets that will make the most impact for their campaign are children and we’ve seen it time and time again. We’ve seen it in Manchester, we’ve seen it worldwide. Children are an easy target for these psychopaths to try and further their political end.

“Islamism and Islamic extremism has never really gone away. We’ve seen a big resurgence since the fall of Afghanistan, where ISIS Khorasan, who were the rogue ISIS branch in the east of the country. They’ve claimed responsibility for the attacks from Russia that happened a few months ago.

“We’ve also seen offshoots, branches in North Africa, and elements in Mali as well.

“So ISIS has never really gone away. It’s just been relatively low profile. But clearly, if you’ve got a scantily clad pop star who attracts an audience of young women and you hate Western society, there’s probably no better embodiment of everything they hate than a Taylor Swift concert, so it makes the perfect target for them.

“You should look and keep your wits about you. The Manchester bombing proved that sometimes these people slip through the cracks. However, we do have exceptionally good counter terrorism police in the UK.

“Our security services have foiled numerous attacks that we’ve never even heard of because they never got far close to committing those atrocities. I don’t think we should be cowering in terror.

“I think we should keep a sense of awareness about this and report anything suspicious to the police. Better safe than sorry, but otherwise, go and enjoy a great night.

“The opposite of letting them win is by going out and enjoying yourself and finding pleasure in a Taylor Swift show.

“Our intelligence services are absolutely top tier. I’ve got friends that work in that space. They’ve told me of some of the things they keep a track on, some of the things they’ve kept an eye on. They are a very impressive bunch and I do have confidence in them.

“I think if I were a security manager for one of these events, a lone wolf would be my number one terrorism concern, the hardest to stop. There’s no network behind them. There’s no trail of buying fertiliser to make explosives. There’s no coordination with them, texting their mates about what they’re going to do.

“They literally go out in a vehicle, with something like a knife sellotaped to their hands to make it harder to take off them, and they do what they plan to do. The event organisers will be firmly aware of this.

“There will be people, especially in the aftermath of Manchester, I think security lessons have been learned. The police will be on duty and there are patterns of behaviour that you can recognize.

“But you can never be 100% safe. As the IRA used to say, we only have to be lucky once. But there are reasonable and sensible precautions in place to make sure that the chances are minimised.

“Radicalization tends to be second and third generation. There are generations of parents who’ve come here that are deeply grateful for the opportunities the UK has given them and deeply grateful to be here and enjoy being part of British society.

“However, there is a minority of recent immigrants who may well be coming here for malign reasons, and it’s impossible to quantify. The fact is, it’s not happening very often, and that’s a good thing.

“The number of serious terror attacks that have been committed by recent arrivals is in single figures, so we can be reassured by that.”