Peter Singer defends the principle of "the good of the many outweighs the good of the few". By paying ransoms for the release of their citizens captured abroad, European governments have saved a few lives, while rewarding criminality and enabling the jihadi groups to enhance their militant activities, like the ones we saw across Iraq and Syria.

When hostages are taken by terrorist groups, rather than by ordinary criminals, the impact of paying ransom can't be underestimated. Al-Qaida in the Islamic Maghreb (Aqim), which for much of its history was an insignificant affiliate of al-Qaida, had grown in size and capability, partly due to income from ransom payments. Governments in north and west Africa have urged Western countries not to pay ransoms, with which terrorists finance their operations, that aime at destabilising the region.

There are no ideal options here. There is the conflict between the general and the particular will. European governments had been under pressure to bring hostages back to their families. But Britain the US take a firmer stand, weighing up the political consequences of letting the jihadists to use the ransom money for violent ends.

Jean-Jacques Rousseau recognised the problematic of complying with the common good and the general will when they are in conflict with individuals' interests. He firmly insisted that the interests of the community should prevail. Protecting the wider public should outweigh the saving of an individual's life. This logic is seen as obnoxious by those affected.

It is a painful decision that governments have to make, when their citizens are kidnapped by Islamists. It explains why the UN Security Council adopted unanimously a resolution in January, "opposing payment of such ransoms", and a similar declaration was made at the G-8 summit in June 2013 in Northern Ireland. A global consensus is the only way to discourage terrorists from making kidnapping a profitable business.