Will ISIS leader Abu Bakr al-Baghdadi one day stand in the dock of the International Criminal Court in The Hague? That may seem an unlikely prospect. But the chances that he and his accomplices will have to answer for their crimes increased last week when the parliamentary assembly of the Council of Europe defined ISIS attacks on religious minorities as genocide. A resolution entitled “Foreign Fighters in Syria and Iraq” declared that the jihadist group had “perpetrated acts of genocide and other serious crimes punishable under international law”. This week the European Parliament was expected to vote on a similar text. These votes will step up pressure on the United Nations Security Council to recognise ISIS atrocities as genocide and refer the case to the International Criminal Court, where the perpetrators would, in theory, be tried. We say “in theory” because ISIS leaders are currently engaged in a deadly battle with dozens of well-armed countries and their long-term survival appears unlikely. But we must not be defeatist. In the last days of the Second World War it must have seemed as if the Nazi leadership would die without being brought before the courts. Yet the Nuremberg trials and later the Eichmann trial ensured some small measure of justice for Holocaust victims. Those trials created an expectation that the international community would, where possible, attempt to prevent genocidal violence. But as Bangladesh, Cambodia and Rwanda have shown, civilised nations are rarely able to act swiftly or harmoniously enough to protect the vulnerable. If prevention is impossible, world leaders must at least take their obligation to punish genocide seriously. Sadly, they appear to be shirking even this responsibility. Witness the struggle to persuade the British Government that ISIS attacks on Christians, Yazidis and other minorities are genocide. As Lord Alton of Liverpool writes in our cover story, the Foreign Office simply shrugs its shoulders when presented with evidence of genocide. One might argue that, as the battle is still raging in Syria and Iraq, it is impossible for the government to say whether ISIS is guilty of genocide. But remember that the UN Genocide Convention of 1948 defines genocide as an act with the intent to “destroy, in whole or in part, a national, ethnic, racial or religious group”. ISIS openly admits it wants to eliminate every group except its own within its territory. Like the Nazis, ISIS documents its atrocities, but it goes a step further: broadcasting them for all the world to see. It is obtuse to argue, at this stage, that there is not enough evidence to say whether ISIS has genocidal ambitions. But clearly the British government will not act until it is shamed into doing so. We should therefore write to our MPs, asking them to add their names to the motion tabled by the Labour MP Rob Flello. We must also pray that the Council of Europe vote will create an unstoppable momentum that will force UN Security Council members to recognise the truth and declare ISIS a genocidal organisation.