It is hard to believe what happened recently to Juhel Miah, a maths teacher from Llangatwg Community School, in Neath near Swansea. He was taken off a plane by American security staff before it took off at Reykjavik. He was told he was not allowed to fly to New York City. No official reason has been received from Washington. Juhel is a Swansea-born UK citizen. He had a valid visa for travel.

His account of what happened next is horrible: deserted in a foreign country, required to stay overnight in a hotel with holes in the sheets and a dirty bag under the bed. He was made to feel like a criminal.

This is shocking enough. But the truly shocking thing is that Miah was accompanying pupils on a school trip. In the words of his headteacher: “Here was a young man, charged with the important task of looking after a group of schoolchildren, being told he had to leave them, with no reason given.”

What on earth was the justification for such draconian action? Why was Miah singled out?

“I can’t think why they wouldn’t want me on the plane, apart from maybe because I’m a Muslim,” said Miah.

Many of us will agree with that conclusion, particularly given that this incident comes in the wake of US president Donald Trump’s so-far failed attempt to ban people from certain Muslim-majority countries from entering the US.

It will certainly have seemed so to the young people who were on the plane. They were accompanied by other adults and continued on their trip safely. But they witnessed an act that will appear to them to have been based on discrimination - and one that increasingly seems to reflect the times in which we live.

Speaking up for Juhel Miah is speaking up for liberty

It is incumbent upon us as educators to stand up against prejudice in all its forms. Our children must witness us speaking out against the rising tide of division we see in the world today and saying clearly that it is intolerable.

Indeed, our own government requires us to do so. It asks us to actively promote the fundamental “British” values of democracy, the rule of law, individual liberty, and mutual respect and tolerance of those with different faiths and beliefs.

On any test, Miah’s experience flies in the face of individual liberty. It is difficult to escape the conclusion that it also flies in the face of respect and tolerance of those with different beliefs.

Miah’s headteacher has said that he is part of the school family and that the school will defend him. He is also part of our education community, and we must defend him, too.

At the very least, the US authorities must provide an explanation for this extraordinary incident, and it is right that the Welsh first minister, Carwyn Jones, has written to foreign secretary Boris Johnson, asking for “urgent clarification” on the case.

We, at the Association of School and College Leaders, will also be pressing for an answer. We must not let this go unchallenged.

We must demonstrate to our children and young people that we are willing to stand up for the values we collectively embrace: the values of individual liberty, respect and tolerance.

Leora Cruddas is director of policy at the Association of School and College Leaders

Want to keep up with the latest education news and opinion? Follow TES on Twitter and like TES on Facebook