Last month, Benjamin Netanyahu, Israel’s prime minister, made two announcements regarding his country’s stance on the Iranian nuclear programme.

First, he said that Israel would not be going ahead with a unilateral military strike on Iran’s nuclear facilities this year, abandoning the much feared “October surprise.” Secondly, he spelled out a new “red line” that Iran will not be allowed to cross as far as its nuclear activities are concerned. This will be the moment when Iran has acquired enough more highly enriched uranium to build one nuclear bomb – a moment that in Mr Netanyahu’s view may come by next summer.

In recent days, Israeli officials visiting London have spelled out the details regarding this new red line. In their view, Iran by next summer will have acquired some 240kg of more highly enriched uranium (that is uranium at a 20 per cent concentration). This could be converted by Iran into enough weapons grade uranium (at a 90 per cent concentration) to provide Iran with one nuclear weapon.

The difficulty for the Israeli government is that while western leaders are relieved that Mr Netanyahu postponed plans for a strike this autumn, they don’t regard his new red line as having much credibility either. Read more