The US government’s plans to prevent nuclear
proliferation have moved from the merely incoherent to positively chaotic
following President Donald J. Trump’s flip-flop over a proposed summit with
North Korea’s Kim Jong-un in Singapore this month. In May he aborted the treaty
his predecessor Barack Obama negotiated in concert with the European Union to
halt Iran’s nuclear enrichment programme in return for a lifting of economic
sanctions. In one short step Trump returned Iran to the c
