In Gulf Capital and Islamic Finance, Aamir A. Rehman, the acclaimed author of Dubai & Co.: Global Strategies for Doing Business in the Gulf States, sheds welcome light on the hows and whys of trillions of dollars of Gulf capital, and Shariah-compliant finance--a fast-growing sector that Standard & Poor's values at $750 billion. In addition to incisive analysis of these dynamic, often unfamiliar…