This study examines the historical roots of the 2026 U.S.–Israel military action against Iran by analyzing the long-term geopolitical, ideological, and strategic developments that have shaped relations among these states. The research synthesizes credible online academic sources to trace the evolution of U.S.–Israel strategic cooperation, Iran’s post-1979 revolutionary foreign policy, and the broader regional security dynamics of the Middle East. By situating the 2026 military confrontation within its historical context, the study highlights how earlier diplomatic alliances, ideological rivalries, and regional power struggles contributed to escalating tensions. The findings suggest that the 2026 conflict cannot be understood as an isolated event but rather as the outcome of decades of political mistrust, security competition, and shifting strategic alignments. Understanding these historical foundations provides deeper insight into contemporary Middle Eastern geopolitics and the persistent volatility of U.S.–Iran and Israel–Iran relations.