In their rather different ways, both pope Francis and Aung San Suu Kyi, who will meet on Tuesday in Yangon, have been seen as world spiritual leaders: Aung San Suu Kyi was a recipient of the Nobel peace prize for her stand under house arrest for human rights. Yet their meeting will be an uncomfortable reminder of the realities of power politics and of the limitations of purely moral authority. Since she took office, and some power, last year, Aung San Suu Kyi has presided over a campaign of brutal ethnic cleansing against the stateless Rohingya Muslims of the country’s north-eastern coastal region. Hundreds of thousands of them have fled to vast refugee camps across the border in Bangladesh, which the pope will visit later this week. Her reputation is irreparably tarnished. There have been demands that she be stripped of her Nobel prize. Her defenders point out that she is not in any position to stop, nor even publicly to condemn, the atrocities. They are carried out by the army and by fanatical Buddhist militias, and she does not control either one.

Perhaps the most terrible aspect of the campaign against the Rohingya is that it appears to be widely popular. The group has been successively marginalised; first stripped of their citizenship and now even of the right to their name. Even Cardinal Charles Bo, the head of the church in Myanmar, whom Francis himself appointed in 2015, has publicly urged his boss not to use the term “Rohingya” on this visit. A militant Buddhist group has threatened retaliation if the pope dares do so. This cannot be taken lightly, in a country where Catholics form less than 2% of the population. Nonetheless, he seems disinclined to yield to this pressure. He has frequently used the term Rohingya this year and called the persecuted minority his “brothers and sisters”.

None of this can have appeared so difficult when the visit was first proposed in May, after Aung San Suu Kyi visited the Vatican and it established diplomatic relations with Myanmar. But this was before the flare-up of violence in August which has led to an unprecedented exodus of refugees and an outpouring of international criticism. The public condemnation has had no visible effect. Is there anything that private diplomacy can achieve? The official schedule for the visit is unusually sparse, which suggests there will be a great many quiet meetings. But if these have any effect, it is unlikely ever to be publicly announced. So the pope appears to be on a hiding to nothing. But it is also offers him an unusual opportunity to demonstrate by his actions and his words that spiritual leadership need not involve the demonisation of unbelievers, but requires a recognition of their humanity.