“Britain should have stayed out of the First World War” says Niall Ferguson

What do you see as the main reasons for the outbreak of the First World War?

It has been very tempting to assign blame to one country or another, and Germany has borne the brunt of the responsibility in the historical literature. However, my feeling is that we can’t simply replicate the war guilt clause of the Treaty of Versailles.

As historians we need to recognise that there was a crisis of the international system in 1914, in which most of the combatants miscalculated in one way or another. They all exaggerated the benefits of going to war and underestimated the costs. There was something inherently flawed about the international system that encouraged those in power to make a series of blunders.

How important was the killing of Franz Ferdinand in terms of the outbreak of the war?

I think it was the catalyst for an explosion. If one thinks simply in causal chains, then that was the first shot of the First World War. Yet many assassinations happened in the early 20th century – it was an extremely popular way of making a political point if you were an extremist of the right or the left. So one has to question why other assassinations didn’t cause world wars, but this particular one did.

When you pose the question like that then you find yourself trying to explain not only why the Serbian intelligence service covertly sanctioned a terrorist act by an extremist Bosnian Serb group but also why, when the Serbian government refused the pretty reasonable demands of the Austrian government to co-operate with an investigation into the terrorist act, the Russians backed the Serbs while the Germans backed the Austrians.

Any answer to this question has to explain why this particular assassination produced not just a war between Austria-Hungary and Serbia, but one also involving both Russia and Germany...