For four consecutive days, oil prices have retreated below the $100-per-barrel threshold, a sustained decline rare enough to suggest that something deeper than routine volatility is at work. The convergence of diplomatic signals from President Trump's United Nations address — raising hopes of renewed US-Iran engagement — and progress on Saudi pipeline repairs has quietly shifted the market's posture from scarcity anxiety to cautious relief. In the long human story of energy and power, this moment reflects how swiftly the calculus of global supply can turn on the twin levers of diplomacy and in