Among the reasons Donald Trump has given for waging war on Iran is the need to destroy its nuclear program and eliminate its missile threat. But had history turned out differently, Iran’s Islamic Republic could have possessed a vast arsenal of advanced long-range ballistic missiles armed with nuclear warheads, able to strike targets hundreds of miles away. All thanks to Israel.

Before the Islamic revolution toppled Shah Mohammad Reza Pahlavi, in 1979, Israel and Iran were close strategic partners. During the monarchy, Iran was the only Middle Eastern country to recognize Israel’s right to exist, and Israel—which needed Iran’s oil—kept a large diplomatic presence in Tehran. The relationship was so close that, before the revolution, Israel was prepared to develop surface-to-surface missiles with Iran behind Washington’s back. Israeli officials even suggested to Iran that such missiles could carry nuclear warheads.