Turmoil in the Middle East has sent investors scrambling for safety once more, reigniting a debate over which assets truly offer protection in times of stress. The choice is complicated, as traditional refuges behave unpredictably. Gold has swung sharply, and the dollar — which has been out of favour in the past year — has bounced back. Here’s a look at how some of the favourites stack up: Greenback passes a test The dollar has arguably performed the best among safe havens this week. The dollar...