While ballistic missiles fired from Iran wouldn’t get close to the UK, just a dozen low-cost drones could bring London to a standstill, writes defence expert Francis Tusa . While Europe invests billions in its land to air defence systems, Britain looks increasingly like the most exposed man of the continent J ust before first light, a re-flagged shadow fleet cargo ship sailing up the North Sea launches a dozen Shahed drones against London. As the UK has no air defence radar looking in this