Allow me to be a little bit politically incorrect, but pragmatic.
The world has decided that it wants to negotiate with Iran over nuclear weapons. Nuclear weapons seem to rank less highly in our collective consciousness these days, but they have lost none of their destructive power in the last 60 years, so any held by Iran must give us cause for concern. So the "world", in their ignorance, sends Lady Ashton, a woman whose sole claim to fame appears to be that she is married to Peter Kellner and whose only experience in negotiating is "negotiating" bills through the House of Lords, which is chicken feed compared to typical business negotiations.
So what do the Iranians do when they see this leviathan of international diplomacy heading their way? They check out her CV and see that she started her career working for the unilateralists at the Campaign for Nuclear Disarmament. Not much of a threat there and the Iranians know that they can outbluff the rest of the world because they dealing with a pacifist.
But even then you would have thought that a deal could be done: the Iranians bought off with cash and technology. Ah yes, my friend, but you have obviously never dealt with the Iranians, or many in the Middle East, for there is a fatal flaw in the make up of people such as Mrs Ashton and even Mrs Clinton, the US Secretary of State which means that the Iranians will never sit downto negotiate with them. For alas, they are women, and in so much as the Iranian President and the Supreme Leader will never be seen to sign a document negotiated with a woman, the whole exercise is a vast waste of time and money, and you, dear tax payer, will be picking up the tab.