If you are an Irish Catholic, and have suffered sexual abuse at the hands of a priest, you were recently read a letter from Pope Benedict that tells you: "You have suffered grievously and I am truly sorry. I know that nothing can undo the wrong you have endured. Your trust has been betrayed and your dignity has been violated."

For any practising Catholic in Rwanda, this letter must be unbearable. For it tells you how little you mean to the Vatican. Fifteen years ago, tens of thousands of Catholics were hacked to death inside churches. Sometimes priests and nuns led the slaughter. Sometimes they did nothing while it progressed. The incidents were not isolated. Nyamata, Ntarama, Nyarubuye, Cyahinda, Nyange, and Saint Famille were just a few of the churches that were sites of massacres.

To you, Catholic survivor of genocide in Rwanda, the Vatican says that those priests, those bishops, those nuns, those archbishops who planned and killed were not acting under the instruction of the church. But moral responsibility changes dramatically if you are a European or US Catholic. To the priests of the Irish church who abused children, the pope has this to say: "You must answer for it before almighty God and before properly constituted tribunals. You have forfeited the esteem of the people of Ireland and brought shame and dishonour upon your confreres."

The losses of Rwanda had received no such consideration. Some of the nuns and priests who have been convicted by Belgian courts and the International Criminal Tribunal for Rwanda, respectively, enjoyed refuge in Catholic churches in Europe while on the run from prosecutors. One such is Father Athanase Seromba, who led the Nyange parish massacre and was sentenced to 15 years in jail by the tribunal. In April 1994, Seromba helped lure over 2,000 desperate men, women and children to his church, where they expected safety. But their shepherd turned out to be their hunter.

One evening Seromba entered the church and carried away the chalices of communion and other clerical vestments. When a refugee begged that they be left the Eucharist to enable them to at least hold a (final) mass, the priest refused and told them that the building was no longer a church. A witness at the ICTR trial remembered an exchange in which the priest's mindset was revealed.

One of the refugees asked: "Father, can't you pray for us?" Seromba replied: "Is the God of the Tutsis still alive?" Later, he would order a bulldozer to push down the church walls on those inside and then urge militias to invade the building and finish off the survivors.

At his trial, Seromba said: "A priest I am and a priest I will remain." This, apparently, is the truth, since the Vatican has never taken back its statements defending him before his conviction.

In the last century, Catholic bishops have been deeply mired in Rwandan politics with the full knowledge of the Vatican. Take Archbishop Vincent Nsengiyumva. Until 1990, he had served as the chairman of the ruling party's central committee for almost 15 years, championing the authoritarian government of Juvenal Habyarimana, which orchestrated the murder of almost a million people. Or Archbishop André Perraudin, the most senior representative of Rome in 1950s Rwanda. It was with his collusion and mentorship that the hateful, racist ideology known as Hutu Power was launched – often by priests and seminarians in good standing with the church. One such was Rwanda's first president, Grégoire Kayibanda, a private secretary and protege of Perraudin, whose political power was unrivalled.

The support for Hutu Power was therefore not unknowing or naive. It was a strategy to maintain the church's powerful political position in a decolonising Rwanda. The violence of the 1960s led inexorably to the 1994 attempt to exterminate Tutsis. These were violent expressions of a political sphere dominated by contentions that Hutu and Tutsi were separate and opposed racial categories. This, too, is one of the legacies of the Catholic missionary, whose schools and pulpits for decades kept up a drumbeat of false race theories.

This turning away from the Rwandan victims of genocide comes at a time when the Catholic church is increasingly peopled by black and brown believers. It is difficult not to conclude the church's upper reaches are desperately holding on to a fast-vanishing racial patrimony.

Perhaps it is time Catholics forced the leaders of their church to deal with a history of institutional racism that endures, if the church is truly to live up to its fine words. Apologies are not sufficient, no matter how abject. What is demanded is an acknowledgment of the church's political power and moral culpability, with all the material and legal implications that come with it.

The silence of the Vatican is contempt. Its failure to fully examine its central place in Rwandan genocide can only mean that it is fully aware that it will not be threatened if it buries its head in the sand. While it knows if it ignores the sexual abuse of European parishioners it will not survive the next few years, it can let those African bodies remain buried, dehumanised and unexamined.

This is a good political strategy. And a moral position whose duplicity and evil has been witnessed and documented. For, it turns out, many people, scholars, governments and institutions inside and outside Rwanda are excavating their own roles in the genocide. The Vatican stands as an exception, its moral place now even lower than that of the government of France for its enduring friendship with genocidaires.