大象传媒

Two days after the attacks on Paris professor of history at Harvard University, Niall Ferguson, published an article in which he compared Europe to the Roman Empire, which let its defences down. He concluded by saying, "Poor, poor Paris. Killed by complacency".

Here, Professor Ferguson explains three challenges that the US and Europe failed to tackle, and which paved part of the road to the 13th November attacks in Paris.

Photo: Reuters