I think Obama sees everything through one lens. Doing nothing in the face of the slaughter in Syria is not only shameful, it is unrealistic. This approach leaves Syria as a broken country and a breeding ground for extremists for decades.

Donald Trump seems to be unconcerned about the Russian aggression in Ukraine. By doing this he tells them that they can go ahead and do what they are doing. That is dangerous.

It's hard to conceive that it would take more forces to provide stability in post-Saddam Iraq than it would take to conduct the war itself and secure the surrender of Saddam's security forces and his army. Hard to imagine.

The Western alliance should have supported the Sunni opposition against the Assad regime from the beginning. As far as Iraq is concerned, if it had stayed stable the way it was in 2008, IS would not have been able to expand in Iraq the way they did. The mistake was that Barack Obama withdrew the armed forces from Iraq too fast.

The most striking thing is that even before Osama bin Laden was killed, he seemed largely irrelevant to the Arab Spring.

I think it's a mistake to rely too much on any one economic factor. It's why investors try to spread their portfolio round.

It's a very bad thing when people exterminate other people, and people persecute minorities.