Everyone is so relieved that the Kenyan election this year did not result in a repeat of ethnic violence after the 2007 election, that we seem to have forgotten that both President Uhuru Kenyatta and Vice President William Ruto have been summoned to appear at the International Criminal Court in The Hague charged with crimes against humanity.
This week Kenyatta was invited to London to attend the conference on Somalia, Kenya's troublesome northern neighbour. Everyone else charged with crimes against humanity by the ICC has been arrested on sight and locked up to await trial.
But instead of slipping on the handcuffs this week, Mr Cameron grasped Mr Kenyatta warmly by the hand and welcomed him to London.
He argues that Mr Kenyatta is cooperating with the court. That remains to be seen. Kenyatta must report to the ICC in The Hague on July 9th, Ruto on May 28th.
There are precedents here. Mrs Thatcher embraced Augusto Pinochet of Chile, another murderous dictator but one who helped Britain during the Falklands war, because he too was an enemy of Argentina.
And Tony Blair embraced Colonel Gadaffi when he dropped his nuclear programme. But their crimes were committed before the ICC was established.
No one seems to have thought about the possibility that a murderous warlord might be elected president of a country which is a close ally of Britain and the US and vital to the security and prosperity of East Africa.
When Britain and 121 other countries ratified the Rome statute establishing the ICC (a further 31 signed but have not yet ratified), it was assumed that states would cooperate with the Court. No one envisaged a situation in which someone indicted for crimes against humanity would be elected president.
So will Kenyatta and Ruto dutifully surrender themselves to the court on their appointed dates? Will they then continue to try to run Kenya by skype from a cell in a Dutch prison for the next few years? Unthinkable.
Even if they agreed to go, Kenyans - including the middle classes - will lie down on the road to the airport to prevent them going.
Never mind that Kenya was given the choice to hold them to account in the Kenyan courts but failed to do so. Never mind that Kenya's international treaty obligations oblige the country to deliver them to The Hague.
Never mind that both should already have been arrested by the Kenyan police and put on a plane, delivered to the court and locked up. They are not going to go.
When Kofi Annan issued the names of those culpable for the murder and mayhem that tore Kenya apart in 2008, he gave them a choice of going to The Hague or being tried in Kenya.
Both Kenyatta and Ruto argued in favour of The Hague rather than the Kenyan courts, believing that somehow it would never happen. When The Hague issued summonses they went swiftly into reverse. Too late! Then they argued that they did not have to come in person. Extraordinarily, given that they are accused of crimes against humanity, no arrest warrants have been issued by the Kenyan state or anyone else.
Many Kenyans believe that the charges will be quietly dropped. They believe that Western governments control the Court and it will do their bidding.
President Obama and or Prime Minister David Cameron, they believe, will simply phone up the International Criminal Court and tell it to drop the charges. That belief will be strengthened by the sight of Mr Cameron greeting their president in London this week.
I used to think that Britain's obligation to the ICC would trump its relationship with Kenyan politicians but now I am not so sure. Either way a major train smash is on the way. I cannot see any way of avoiding it. It's either the end of the ICC or a deep rift between those committed to the ICC and Africa.
It sounds like a perfect opportunity for China - another ICC non signatory - to strengthen its already dominant new position in Africa.
Western countries, Britain in particular (being Kenya's closest ally outside Africa) are faced with a hard choice: abandon the ICC or isolate their closest political and security ally in East and the Horn of Africa. Britain and western countries benefit hugely from a stable, prosperous Kenya.
In Mombasa Kenya has the best port on the western Indian Ocean. 5000 Kenyan troops are in Somalia helping to restore peace and Britain is taking the lead in establishing a legitimate government there. A huge space in northern Kenya is also the British army's training ground for hot weather warfare. British troops heading to Afghanistan spend time acclimatising to hot conditions and training there. And Britain wants economic success stories in Africa.
Kenya has a dynamic economy and has just discovered oil. Five of the top ten tax paying companies in Kenya are British and economic ties are strong. At a time of fragile security in the whole of the Horn of Africa as well as the growing economic influence of China in the area, is this the moment to put Kenya in the deep freeze?
Against this argument is the demand for a system of international justice where politicians are no longer above the law and can hire gangs of thugs and hit-men to destroy their opponents.
In Africa however there is a strong feeling that the ICC is specifically targeting those from the continent. The vast majority of those convicted by the ICC and its affiliates are indeed African. The only president facing trial is Omar Beshir of Sudan who has been charged with crimes against humanity in Darfur. There was once talk of sending snatch squads to capture him but he travels around Africa freely with no threat of arrest in most countries.
So what will happen? Unless anything changes, when Kenya fails to deliver those charged to The Hague it will be punished by international sanctions. As Johnny Carson, the retiring United States Assistant Secretary of State for Africa, said "choices have consequences". America's president may be half Kenyan but he is not sentimental about it.
Contact with Kenya by countries who have ratified the ICC charter will be reduced to a minimum - essential business only. The President and Vice President of Kenya will be unable to travel except to countries that do not recognise the court
. Aid to Kenya, including training the Kenyan armed forces, will be cut. British and US naval ships will stop using Mombasa port. Kenyans will find it harder to come to Europe and the US.
The fact is that the Kenyan elite - like many in Africa - simply do not recognise that they are subject to the law. Politically powerful, exceedingly wealthy and above the law, no state official would dare touch them.
Throughout the years they have regularly looted the state through scams such as Goldenburg and Anglo Leasing but not one of them has been sent to jail. That is why the rest of the Kenyan elite have rallied round and supported them in the name of nationalism fighting off "British colonialism".
There are some manoeuvres that Kenyatta, Ruto and the others accused can deploy to delay their trials. Kenya could repudiate the treaty, withdraw from the court and refuse to send those accused for trial.
There is widespread demand in Kenya and elsewhere in Africa to withdraw from the ICC but under international law that would not affect the cases already started.
After that the options narrow. For example under Chapter VII, the UN Security Council can adopt a resolution requesting the Court not to commence an investigation or prosecution for up to 12 months.
Kenyatta and Ruto have both requested a delay in the beginning of the trial and asked if they can appear by video link or that the trial is held in Kenya or Arusha (Tanzania). The court is looking at a request for delay in Kenyatta's trial until November but it looks unlikely to bend on other issues.
The larger threat is that witnesses will be prevented from attending. At least two key witnesses in the Kenyatta case are reported to have either disappeared and are believed to have been murdered. Others have withdrawn their statements. The case might collapse.
The case against Ruto is said to be much stronger. Ruto is the Kalenjin leader and the worst killing that took place in 2008 was between Kalenjin and Kikuyu.
Kenyatta and Ruto then established an ethnic alliance which made sure the war between them did not break out again and their combined numbers would secure electoral victory. But if Ruto goes to The Hague but not Kenyatta there may be war between the two groups again.
Whichever way you look at it a major diplomatic earthquake is about to happen.