"Discrimination doesn't come naturally. It is taught."

With simple, stinging words, Nobel laureate Desmond Tutu offered a reminder of how far humans will go in the name of their differences.

His intervention — a rebuke — was an open letter to de facto Myanmar leader Aung San Suu Kyi, condemning her refusal to call out the horror endured by the minority Rohingya Muslims in her country.

But within was also an indictment of the world's muted reaction to the violence against, and extraordinary displacement of, thousands of people who are already labelled the most persecuted minority in the world.

"We know that you know that human beings may look and worship differently — and some may have greater firepower than others," he writes.

Nobel laureate Desmond Tutu: 'When you scratch the surface we are all the same.' (The Associated Press)

"But none are superior and none inferior … when you scratch the surface we are all the same."

But to be Rohingya in 2017 is to be The Other. It is to face that most enduring and insidious human sentiment: bigotry.

And they are facing it not only in Myanmar, where bigotry is at the root of their longtime effective quarantine, but also from the wider world, where prejudice has long manifested itself as indifference.

"We are friendless in our own country: because we are racially different, we are religiously different and our appearance is different," says Tun Khin, a U.K.-based Rohingya Muslim activist whose family fled an earlier wave of violence to Bangladesh. He is president of Burmese Rohingya Organization UK.

"We are witnessing the most horrific situation in our history."

This Aug. 30, 2017 photo shows Rohingya refugees reach for food aid at Kutupalong refugee camp in Ukhiya near the Bangladesh-Myanmar border on Aug. 30. (AFP/Getty Images)

Long before the latest violence sent 270,000 Rohingyas pouring across the border to Bangladesh, fleeing for their lives, they lived a bleak existence.

Once afforded rights as an ethnic minority among a majority Buddhist population—Khin says Burma once even had a radio station in Rohingya language, and his grandfather served as a parliamentary secretary—things changed following a 1962 military coup.

Since then, their rights have gradually been removed. They have been segregated in the Rakhine state and denied education and freedom of movement.

Though many have been in Burma for generations, they are considered illegals and were effectively stripped of the right to citizenship in 1982. Hundreds of thousands who fled earlier violence haven't come back.

Rohingya refugees at a crowded camp in 2012 on the outskirts of Sittwe, Myanmar. The UN calls them one of the most persecuted minorities in the world. (Paula Bronstein/Getty Images)

"There's no safety and security… you are living like a hell. [An] open prison."

And none of this is new. As a persecuted people, they have long been neglected by the world, even when it championed the cause of democracy in Burma.

When elections finally happened in 2015, Rohingya were not allowed to vote. Still they hoped their lot might improve when Aung San Suu Kyi, an opposition activist who was put under house arrest by the military, became the state counsellor.

Khin, who campaigned for her release back then, is bitterly disappointed.

When she was under house arrest, "she mentioned that, 'please use your liberty to promote ours.' Now I want to ask Aung San Suu Kyi: Please use your liberty to promote ours."

Feels well planned

The Myanmar military undertook the current "clearance operations" after Rohingya militants attacked government forces on Aug. 25, killing and injuring many among them.

Rohingya Muslims say they condemn the violence, but the military's response amounts to collective punishment. Bolstered by Buddhist nationalists, the violence, to the Rohingya, has the feel of being well planned. They believe it is a continuation of a sustained campaign to wipe them out.

Khin calls it ethnic cleansing, a slow genocide.

During earlier flare-ups, Suu Kyi said ethnic cleansing was "too strong" a term.

Aung San Suu Kyi doesn't have the power to halt military operations, but many of her supporters, including Desmond Tutu, insist she has the moral standing and obligation to do so. (Jorge Silva/Reuters)

This time around, she's quoted as saying there was a "huge iceberg of misinformation" surrounding the crisis, but that "we have to take care of everybody who is in our country whether or not they are citizen — it is our duty, and we try our best."

Suu Kyi doesn't have the power to order a halt to the military's operations.

But many of her supporters, including Tutu, have insisted she has the moral standing—and obligation—to do so.

They also insist this isn't a legal or immigration question. It is a human rights question, a dangerous case of mass discrimination, prejudice, racism and ultimately, hate.

"She was the one person in the country who really could have challenged this really ingrained and endemic prejudice against Muslims in the country and Rohingya in particular," Mark Farmaner, of Burma Campaign UK, told CBC News.

Get to root causes

Her government has kept in place all the policies of the previous military regime, he added. They use "the combination of human rights violations, and deliberate impoverishment, to force Rohingyas to leave."

This week, UN Secretary General Antonio Guterres advised getting to the root causes to solve the crisis.

"It will be crucial to give the Muslims of Rakhine state either nationality or, at least for now, a legal status that will allow them to have a normal life—including freedom of movement and access to labour markets, education and health services."

A Rohingya refugee from Myanmar's Rakhine state holds a baby as she sits in a makeshift shelter after arriving at the Kutupalong refugee camp near the Bangladeshi town of Teknaf on Sept. 5. (KM Asad/AFP/Getty Images)

But to the hellish turn of events in the past weeks, world leaders have so far only offered couched words.

Many have only this week expressed concern—or any hint of support for Bangladesh, an already impoverished country that must contend with a huge added responsibility.

World powers continue to support a leader who appears to be maintaining her position at a cost that Tutu described as "surely too steep."

Khin says some of those countries help train and equip the Myanmar military and can send a powerful message by suspending that support.

Peacekeepers must be sent in, he added. Suspended aid in Rakhine state must be restored. Willing media should be allowed to monitor.

"It's not a time to condemn by releasing statements and mentioning their concern," said Khin. "It is time to act."