For emerging-markets economies, it’s a sign of maturity to develop truly world-class enterprises. Mexico can boast of cement producer Cemex, Brazil of aircraft maker Embraer, South Korea of electronics giant Samsung or automaker Hyundai.

In Turkey arguably the best claim to such lofty status belongs not to an industrial company but to a pension fund — and the military’s at that. Ordu Yardimla¸sma Kurumu, or OYAK, as it is known, operates like a private equity fund rather than a portfolio investor, is more profitable than any of Turkey’s family-run conglomerates and enjoys a higher credit rating than the government. The man responsible for that success, Co¸skun Ulusoy, is a military history buff who approaches the art of the deal like a general preparing for battle. Since taking over as CEO in 2000, his investing acumen has helped OYAK deliver a sixfold increase in retirement benefits to the country’s...