The FTSE 100 has tumbled after hopes of a peace deal in the Middle East hit shares in oil and defence companies. London’s premier stock index fell 1.5pc on Thursday, more than other markets across Europe and in the US. Defence majors BAE Systems and Babcock International sank by 5pc and 2.2pc respectively following reports that the US and Iran were close to reaching a peace deal. Shares in BP were down by 2.6pc while Shell dropped by 2.9pc after oil prices fell below $100 a barrel on hopes that