16 June 2010: It is not clear what has provoked the US to decide to oppose Chinese plans to export two nuclear reactors to Pakistan at an upcoming Nuclear Suppliers' Group meeting. Up to two weeks ago and more certainly in early May, the Barack Obama administration was veering towards letting the deal go through in exchange for China's support for the Iran sanctions. The US cannot have made a compact on Iran to renege opportunistically later. Nations and especially competing great powers cannot afford to break pledges so artlessly.