The "termination" of the nuclear deal with Iran and the "destruction" of the transatlantic alliance between the EU and the U.S. are "bound to have a negative effect on the European economy and cause other dislocations," including a devaluing of emerging-market currencies, Soros said in a speech in Paris on Tuesday. "We may be heading for another major financial crisis."

The stark warning from the billionaire money manager comes as Italian bond yields have jumped to multi-year highs and major emerging economies including Turkey and Argentina are struggling to contain the fallout from runaway inflation. Soros, who has been the object of ire by the government of his native Hungary, saved his gloomiest outlook for the EU.