From a geo-strategic point of view, I consider Iran a bigger problem than the Islamic State. ISIS is a group of adventurers with a very aggressive ideology. But they have to conquer more and more territory before they can became a geo-strategic, permanent reality. I think a conflict with ISIS - important as it is - is more manageable than a confrontation with Iran.

Well, he keeps saying that, and as defense secretary, of course he has to think of a lot of potential enemies. I do not think it's a wise course to articulate this or to base our policy on it. And I do not see under modern circumstances what we would be fighting about.

It is frankly a mistake of amateurs to believe you can gain the upper hand in a diplomatic negotiation.

I think a resumption of the Cold War would be a historic tragedy. If a conflict is avoidable, on a basis reflecting morality and security, one should try to avoid it.

An expert is someone who articulates the needs of those in power.

Leaders are responsible not for running public opinion polls but for the consequences of their actions.

Administration has managed the extraordinary feat of having, at one and the same time, the worst relations with our allies, the worst relations with our adversaries, and the most serious upheavals in the developing world since the end of the Second World War.