Markets should look for "a significant additional political risk premium on the price of Brent" if nuclear arms talks between Iran and major world powers break down, Nomura has warned.

If Iran walks away from the negotiation table over the proliferation of nuclear weapons technology in the country, markets could easily be spooked over the region's stability and that could affect the price of Brent, which has tumbled since June, Nomura's senior political analyst Alastair Newton said in a note Thursday.