Today, on the anniversary of the September 11, 2001, terror attacks on America, parents across the country are telling their children what happened on that horrible day 16 years ago.

But the same isn't happening everywhere in the world. Some places are just too politically correct to say the truth: that radical Islamists attacked the world — anyone and everyone who isn't like them. (More than 60 countries had citizens who died in the attacks; see this map.)

The United Kingdom lost 67 citizens that day. But some U.K. teachers are simply too terrified to teach their students about the attacks because they fear a backlash from Muslim parents, a leading expert in counter-extremism education told The Telegraph.

Kamal Hanif OBE, who was appointed by the Government to turn around three schools at the heart of the “Trojan Horse” scandal, said that some teachers have a “misplaced” concern that they will cause offence if they raise 9/11 in the classroom.

He said that some teachers — particularly those who work in schools with a high proportion of Muslim students — see it as a contentious topic and shy away from teaching it.

“Teachers sometimes have a fear that this might be controversial,” he said.

“[They think] if we teach about this we might get Muslim parents objecting.”

Mr Hanif, who is executive principal of Waverley Education Foundation and has advised the Department for Education (DfE) on combating counter-extremism in schools, said that such views are misguided.

“There is a fear [among teachers] but it is not really grounded in anything,” he said.

“It is based on their stereotypical view of a community as opposed to the reality. It is very misplaced. It is an assumption.”

Sixteen years ago, 2,958 people were murdered by Islamic terrorists. More British citizens died that day than in any other terrorist attack.

And that ought to be taught to young British citizens.

Never forget.