France, Britain and Germany warned Russia on Saturday that its demands to have its trade guaranteed with Iran risked the collapse of an almost-completed nuclear deal. Negotiators have reached the final stages of discussions to restore the so-called JCPOA deal, which lifted sanctions on Iran in return for curbs on its nuclear programme, long seen by the West as a cover for developing atomic bombs. However, last Saturday Russian Foreign Minister Sergei Lavrov unexpectedly demanded sweeping guarantees that Russian trade with Iran would not be affected by sanctions imposed on Moscow over its invas…