Dubai. The Persian Gulf emirate garnered worldwide attention when Halliburton announced it would move its chief executive there from Houston. It’s the most visible in a growing wave of energy-industry migration from the United States to the Middle East. As a bonus, Dubai and other emerging economies, from the Persian Gulf to China, are taking advantage of the weak dollar and buying major stakes in U.S. companies and real estate.Loren Steffy is the Chronicle’s business columnist. His commentary appears Sundays, Wednesdays and Fridays. Contact him at email@example.com. His blog is at http://blogs.chron.com/lorensteffy/.