Type 2 diabetes mellitus (T2DM) has become a modern-day plague by reaching epidemic levels throughout the world. Due to its similar pathogenesis, gestational diabetes (GDM) increases in parallel to T2DM. The prevalence of T2DM (3.9–18.3%) and GDM (5.1–37.7%) in countries of the Arab Gulf are amongst the highest internationally, and they are still rising precipitously. This review traces the reasons among the Arab nations for (a) the surge of T2DM and GDM and (b) the failure to contain it. During the last five decades, the massive oil wealth in many Arab countries has led to the unhealthy lifestyle changes in physical activity and diet. The excess consumption of calories turned the advantageous genes, originally selected for the famine-like conditions, detrimental: fueling obesity and insulin resistance. Despite genetic differences in these populations, GDM—a marker for future obesity and T2DM—can overcome this scourge of T2DM through active follow-up and screening after delivery. However, the health policies of most Arab countries have fallen short. Neglecting this unique chance will miss an irreplaceable opportunity to turn the tide of the T2DM and obesity epidemic in the Middle Eastern Arab Gulf countries—as well as globally.