“Mr Obama sought to give reassurances at the weekend. While cautioning against “loose talk of war”, he declared that the US did not have a policy of containment towards Iran’s nuclear programme. On the contrary, his policy was to prevent Iran from acquiring a nuclear weapon and he retained the option of using force to do this.

That is the right message in principle and it reduces the risk of conflict. Whenever Iran has been caught cheating on its obligations to the IAEA and the UN Security Council, it has smartly stepped back in line with them. The best hope of averting the need for a military strike against its nuclear facilities is to convince Tehran of the seriousness with which its duplicity is regarded.

Israel faces what its leaders term an existential threat if Iran’s nuclear adventurism proceeds. Mr Netanyahu seeks reassurance that the US will keep open its options for countering an Iranian nuclear weapon and will not abdicate its responsibilities to prevent that outcome. For once, he is right.”