Reuters

The leader of Britain's opposition Labour party, Jeremy Corbyn.

It's been an awfully long time since a frontline politician had to clarify whether he was, in fact a pacifist. It's taken as read that, should the need arise, political leaders will put British (or American) troops into harm's way.

Jeremy Corbyn is not a consensus politician, though. His previous campaigning efforts made the clarification necessary. The Labour leader, hoping to be elected as prime minister in under a month's time, needed to let the electorate know if they were voting in someone who wouldn't ever use violence.

'I am not a pacifist,' Corbyn said, 'I accept that military action, under international law and as a genuine last resort, is in some circumstances necessary.'

Going on to suggest that he would have endorsed the Second World War, Corbyn insisted however, 'that is very far from the kind of unilateral wars and interventions that have almost become routine in recent times'.

So, can a prime minister ever be a pacifist? And surely being a pacifist is a good thing? Well...

Christian teaching has broadly fallen into one of two camps. The first is Christian pacifism. Arguably the mode modelled by the early Church, pacifists draw their inspiration from Jesus' teaching in the sermon on the mount.

In Matthew 5 Jesus says, 'I say to you, Do not resist an evildoer. But if anyone strikes you on the right cheek, turn the other also.' Taking this teaching literally, the Christian pacifist tradition was adopted by Anabaptists after the Reformation and is expressed most strongly today by Quakers, Mennonites, Amish and other related groups.

Probably the leading exponent of this tradition today is the theologian Stanley Hauerwas. He argues 'that Christians are called to nonviolence not because our nonviolence promises to make the world free of war, but because in a world of war we, as faithful followers of Jesus, cannot imagine being other than nonviolent'.

The other tradition is known as Just War theory. Formulated via two of the Church's most important theologians, St Augustine and St Thomas Aquinas, the theory survives into the modern day.

It suggests a tight range of criteria on which a war may be permissible according to Christian doctrine. In a recent piece for the Catholic Herald, theologian Matthew A Shadle said, 'The Church's ethic of war and peace is not fundamentally about using technology in the right way, but about devoting our energies to promoting peace, even if that means that in the worst situations we resort to arms.'

While some theologians have backed many of the recent American and British overseas interventions, including the disastrous invasion of Iraq, on the basis of Just War theory, proponents of both positions have been heavily critical too.

It's important not to think Just War advocates as warmongers, and pacifists as peace lovers. Both traditions strive for peace, but differ in how it should be achieved.

With these two traditions being debated and refined in light of the end of the Cold War, the rise of international terrorism, and the ongoing conflicts in the Middle East, the question remains, can a prime minister be a pacifist?

Put another way, the question is really – should we expect secular political leaders to be able to follow the demands of Christian pacifism?

Greg Boyd, an Anabaptist theologian and pacifist says Christians should behave differently to the secular authorities. 'I don't believe Jesus' and Paul's teaching on the need for disciples to adopt an enemy-loving, non-violent lifestyle was ever intended to serve as a mandate for how governments are supposed to respond to evil,' argues Boyd.

Those critical of the pacifist position would argue that Christians who swear off all violence aren't merely being neutral or prophetic, though. George Orwell was scathing when writing of pacifism during the Second World War. 'Pacifism is objectively pro-Fascist,' wrote the man who had put his own convictions on the line while fighting in the International Brigades during the Spanish Civil War. 'This is elementary common sense. If you hamper the war effort of one side you automatically help that of the other. Nor is there any real way of remaining outside such a war as the present one.'

While Christians disagree on whether violence is ever justified, it would seem unlikely that the Church is ever going to speak with a unified voice to politicians, such as Jeremy Corbyn. And can a pacifist ever be Prime Minister? Possibly not.