In considering the visit to London of the Egyptian president Abdel Fattah el-Sisi, I can do no better than to quote the words of Amnesty International in its most recent report on Egypt:
"The [past] year saw a continued dramatic deterioration in human rights following the ousting of President Mohamed Morsi in July 2013. The government severely restricted freedoms of expression, association and assembly. Thousands were arrested and detained as part of a sweeping crackdown on dissent, with some detainees subjected to enforced disappearance.
"The Muslim Brotherhood remained banned and its leaders were detained and jailed. Torture and other ill-treatment of detainees remained routine and was committed with impunity. Hundreds were sentenced to prison terms or to death after grossly unfair trials. Security forces used excessive force against protesters and committed unlawful killings with impunity.
"Women faced discrimination and violence. Some refugees were forcibly returned. Forced evictions continued. Dozens of people faced arrest and prosecution for their sexual orientation or identity. Courts imposed hundreds of death sentences; the first executions since 2011 were carried out in June."
What impressive dexterity our prime minister is demonstrating. In February 2011, there he was, grandstanding in Tahrir Square, celebrating with Egypt's pro-democracy activists the overthrow of the country's former leader, Hosni Mubarak. And here he is now, less than five years later, warmly welcoming Mubarak's successor, the former field marshal who seized power in a coup that ended Egypt's imperfect experiment with democracy.
To many Egyptians, Sisi is even worse than Mubarak. According to a new report by the Geneva-based human rights organisation Alkarama, more than 320 people have died in Egyptian jails since the military coup in July 2013, "direct consequences of torture, ill-treatment or denial of medical care." More than 1,000 people were killed during the protests that followed the coup.
And yet. When Egyptians look at what has happened in Libya and Syria, many will conclude that they would rather stick with Sisi. For the region as a whole, as well as for the Western powers, a military-backed autocrat may look far preferable to the terror of IS. It is also far from irrelevant that Israel depends on Egyptian cooperation to keep Hamas bottled up in Gaza.
Egypt is by far the most important Arab nation in terms of size and population. There are more people living in Cairo alone than in all of Libya. It would be in no one's interests - least of all its own people's - for it to descend into anarchy, and the brief rule of the Muslim Brotherhood's President Morsi was hardly an example of liberal democracy in action.
It's only a couple of weeks since President Xi Jinping of China was in town, so there was barely time to get the red carpet cleaned. Perhaps Downing Street should get a new one made: it could have the words "raison d'état" embroided in silk thread along its entire length. Dictionary definition: "a purely political reason for action on the part of a ruler or government, especially where a departure from openness, justice, or honesty is involved." Which seems to sum it up perfectly.
President Xi was here because he brought with him the promise to invest billions in the UK economy; President Sisi followed in his footsteps because he brought the promise of cooperation in a confrontation with jihadi groups that Mr Cameron has called "a generational struggle against a poisonous and extremist ideology." Plus, of course, the prospect of some more orders for British-made weaponry.
How horribly embarrassing, therefore, that on the eve of Sisi's arrival, the UK in effect accused Egypt of such ropey security procedures at Sharm el-Sheikh airport that they somehow allowed a bomb to be smuggled on board a Russian plane, causing it to explode with the loss of 224 lives. As a result, some 20,000 British holidaymakers were left stranded when all British flights to and from the airport were suspended.
In a BBC interview this week, President Sisi insisted that he has "a roadmap for real democracy in Egypt" and that it will be for Egyptians to decide what role, if any, the banned Muslim Brotherhood should have in the country's future.
That will be hard to believe for the thousands of Brotherhood supporters currently languishing in Eypt's dismal jails - and even harder to believe for 28-year-old Sondos Asem, who was foreign media spokeswoman for the Brotherhood during the ill-fated reign of President Mohamed Morsi and who was sentenced to death in her absence last May.
Talking to world leaders - even world leaders with blood on their hands - is part of the job description when you move into 10 Downing Street. Saying nothing publicly, or nothing meaningful, about their worst excesses is not. So next time Mr Cameron hosts a leader with a woeful human rights record, perhaps he could bring himself to say something about it. In public.
Then we could at least try to convince democracy activists, whether in China, Egypt, or elsewhere, that we are not ignoring them. I'm sure they would appreciate it.