The central achievement of the Iran nuclear deal – keeping Tehran at arm’s length from nuclear weapons – is eroding.  The 2015 accord’s many restrictions on Iran’s atomic activities were built around one objective: to extend the “breakout time” Tehran would need to produce enough fissile material for one atomic bomb – if it decided to do so – to at least a year from around 2-3 months. Iran maintains that it has never sought nuclear weapons and never would. It has long said it has enriched for civilian purposes including future nuclear energy and research projects. Tehran began breaching the deal’s curbs last year in a step-by-step response to President Donald Trump’s withdrawal of the United States from the deal in May 2018 […]