For decades, the Saudi-American alliance has rested on a quiet compact: oil and stability in exchange for security and influence. Now, as coordinated strikes chip away at the kingdom's energy infrastructure and Iran's shadow lengthens across the region, that compact is showing its seams. The Trump administration has offered support, but support with limits — and in Riyadh, the distance between what was promised and what has arrived is forcing a long-deferred question about whether one great alliance is enough to anchor a kingdom's survival.