The Rohingya crisis "seems a textbook example of ethnic cleansing", according to the United Nations' human rights chief.
But it is not yet officially genocide.
One can only wonder why not, given the definition of the crime in Article II of the UN's Genocide Convention.
It states that genocide is any of the following acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group:
(A) Killing members of the group;
(B) Causing serious bodily or mental harm to members of the group;
(C) Deliberately inflicting on the group conditions of life calculated to bring about its physical destruction in whole or in part;
(D) Imposing measures intended to prevent births within the group;
(E) Forcibly transferring children of the group to another group
Myanmar's government seems to have met at least A-C of the above criteria. So why the reluctance to call the mass killings and forced deportations genocide?
To answer that we must look to Article I of the same convention.
It says: "The contracting parties confirm that genocide, whether committed in time of peace or in time of war, is a crime under international law which they undertake to prevent and to punish."
That's why the word isn't being used.
Defining events like this as genocide requires the 147 nations that have signed up to the convention to stop it – by force if necessary.
That's why back in 1994 the US State Department was swiftly gagged by its own lawyers during the mid-stages of the Rwandan genocide.
They pointed out that if the US accepted that the mass murder of around one million was state-sponsored and ethnically-based then there was an obligation to invade the central African nation.
Instead, the US, UK, and every other country wrinkled their noses at the mass murder of Tutsis and moderate Hutus until it was all over and any effort to prevent the slaughter would have been too late.
There's no appetite to invade Myanmar. Not least because its leader Aung San Suu Kyi is a Nobel peace laureate.
And so the Rohingya, a Muslim population in a largely Buddhist nation, are being "ethnically cleansed" not subjected to genocide – not that they would be able to tell the difference.