Saudi Crown Prince Mohammed Bin Salman stunned the Middle East this weekend by declaiming that “the Iranian Grand Ayatollah Ali Khamenei is the new Adolf Hitler of the Middle East.”He added that Khamenei must be stopped to save the Middle East.In recent weeks there has been much talk of improved relations among Saudi Arabia, Egypt and Israel. There are persistent rumors that the reward for Israel joining the battle against Iran would be leading Arab states’ willingness to cede east Jerusalem to Israel and make Ramallah the capital of a Palestinian state.Two questions immediately pop up. Why are the Saudis and their allies willing to forgo generations of refusing to recognize Israel and turn it into a major ally? And why are the Israelis likely willing to accept this role? It is important to remember that in war and politics radical change in alliances is not unprecedented. In World War II the democratic capitalist United States and Great Britain had the communist Soviet Union under Josef Stalin as their main ally. In World War I antiquated Tsarist Russia allied with democratic modern France and Great Britain. In the American Revolution the Americans aligned themselves with the autocratic French empire of King Louis XVI against a semi-democratic Great Britain.Most importantly, the Saudis look at how Iranian forces and allies are sweeping the Middle East in Lebanon, Iraq, Syria and Yemen.Even though the Saudis have been spending money on their military at a furious pace, many analysts doubt the Saudis could fend off Iran one on one. Their possible allies – Egypt, Jordan, the United Arab Emirates – have their own limitations.Iran will likely have nuclear weapons in the next decade or sooner thanks to the deal with the United States and Western Europe.But Israel is another matter.The Israeli military is often cited as the best military force in the Middle East and among the top 10 militaries in the world. It has been seasoned in 11 wars since the creation of the state in 1948. Israel has been a nuclear power since the 1960s and currently has 100- 200 atomic bombs, nearly 700 aircraft and 2,600 tanks.Israel has a close military relationship with the United States, with over $38 billion in equipment to be sent to Israel in the next 10 years. It has some of the best trained military manpower in the world.Its nuclear weapons can be delivered by sea (Dolphin class submarines), air (even by F-35 jet fighters) and land (missiles). Furthermore, it has developed together with the US the most modern anti-missile missile defense system in the world, with shortrange missiles (Iron Dome), mid-range missiles (David’s Sling) and long-range missiles (Arrow 3). It also is a top five power in the vital 21st century high-technological sphere with over 320 foreign companies doing half or more of their R&D Israel. It has some of the best intelligence agencies in the world.Even better from the Arab perspective, the Israelis rate Iran as posing most of the threat they face in the coming years. There is virtually no danger that Israel would ever turn on Saudi Arabia and Egypt. Meanwhile, the Iranians are again facing an uprising, and history shows that eventually the revolution will triumph. The Israelis would gain much and lose little from aligning with Saudi Arabia and Egypt.And so, as in ancient India, the enemy of my enemy turns out to be my friend.So much has changed, yet so much remains the same.The author is a professor at the Josef Korbel School of International Studies, University of Denver.