After more than three decades of on-and-off construction, the sinister-looking Ryugyong Hotel in Pyongyang is finally poised to open in mid-2013. The pyramid-shaped structure, which rises 105 stories, will be the world’s tallest hotel — and one of the few that evokes an intergalactic warhead. Reto Wittwer, the chief executive of Kempinski Hotels, is over the moon that his firm won management rights. “This pyramid monster hotel will monopolize all the business in the city,” he said recently. “I said to myself, ‘We have to get this hotel if there is ever a chance, because this will become a money-printing machine if North Korea opens up.’”