Breaking the nuclear deal ratchets up the conflict between Iran and America

THE FACILITY 30km (19 miles) north-west of the Iranian city of Natanz looks like a humdrum industrial site. Only the anti-aircraft guns hint at what goes on eight metres (26 feet) underground. For over a decade Iranian scientists there have fed uranium hexafluoride into centrifuges that spin at twice the speed of sound so as to sift out uranium-235, the isotope capable of sustaining a chain reaction in a nuclear power plant or bomb. The “raw” uranium that goes in is 0.7% ²³⁵U; the stuff that comes out is 4% ²³⁵U.