UAE President Sheikh Khalifa bin Zayed ruled for 18 years (2004-2022) before his death on May 13 -- less than half that of his father Sheikh Zayed, who reigned from 1971 to 2004. Yet in some ways, Sheikh Khalifa's shorter tenure was packed with more complications, as geopolitical pressures forced the United Arab Emirates to evolve beyond the simpler oil-for-power politics of Sheikh Zayed's time. Now it's his brother's turn to define an era. For Sheikh Mohammed bin Zayed Al Nahyan, who is known by the acronym MbZ and was elected president by his fellow rulers on May 14, the future is ripe with opportunities to impress his vision for the future on not only the United Arab Emirates but the wider Middle East region....