On Syria, it is hard to see anything of substance emerging. Last year’s successful Libya operation in which the United States was content to take a “followership” role is not going to be replicated in the infinitely more complex context of Syria. But the most intractable issue facing the two leaders will be Iran. Israel is increasingly – and understandably – restive about the existential threat that would be posed by a nuclear-armed Iran and now talks openly about launching a pre-emptive strike. That may explain why Iran’s supreme leader, Ayatollah Ali Khamenei, last week welcomed President Obama’s statement that there was still a “window of opportunity” to resolve the dispute over Iran’s nuclear programme peacefully. Such conciliatory language is rare, leading some to conclude that Tehran is looking for a diplomatic way out of the impasse. Wishful thinking, perhaps – but this week’s US-UK talks will offer a timely opportunity to explore this proposition.