The United States and Israel's joint military campaign against Iran is upending the strategic order of the Middle East in ways that extend far beyond Tehran. The strikes have killed Iran's Supreme Leader Ali Khamenei, targeted Iran's military and nuclear infrastructure, and triggered retaliatory Iranian attacks across the region. As the war enters its second week, a second and potentially more consequential shift is taking shape. With Iran's role as the dominant pole of regional opposition to Israel now in question, a new rivalry is hardening between Israel and Turkey, one that carries different stakes, different risks, and a far more unpredictable trajectory than the confrontation the current war was designed to resolve. Understanding this emerging fault line requires examining both the structural forces pushing the two states apart and the domestic political dynamics that risk turning competitive rhetoric into irreversible confrontation.