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 Rabin's 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 Iran's development of nuclear technology relative to Israel's long-stated Begin Doctrine, Iran's funding of Islamist groups such as Hezbollah, Palestinian Islamic Jihad and Hamas, as well as alleged involvement in terrorist attacks such as the 1992 attack on Israeli embassy in Buenos Aires and the 1994 AMIA bombing, and Israel's alleged support for militant groups such as the People's Mujahedin of Iran and Jundallah as well as alleged covert Israeli operations in Iran including mass assassinations and bombings. Since 1985, Iran and Israel have been engaged in an ongoing proxy conflict that has greatly affected the geopolitics of the Middle East, and has included direct military confrontations between Iranian and Israeli organizations, such as in the 2006 Lebanon War.