 Complete the following phrase:  After the 1979 Islamic Revolution, Iran severed all diplomatic and commercial ties with Israel, and its theocratic government does not recognize the legitimacy of Israel as a state. The turn from cold peace to open hostility began in the early 1990s, shortly after the collapse of the Soviet Union and the defeat of Iraq in the Gulf War, after which relative power in the Middle East shifted towards Iran and Israel. The conflict escalated in the early 1990s, as Yitzhak Rabins government adopted a more aggressive posture on Iran. Rhetorical conflict heated up during the presidency of Mahmoud Ahmadinejad, who made inflammatory statements against Israel. Other factors that have contributed to the escalation of bilateral tensions include Irans development of nuclear technology relative to Israels long-stated Begin Doctrine, Irans funding of Islamist groups such as Hezbollah, Palestinian Islamic Jihad and Hamas, as well as alleged involvement in terrorist attacks such as the 