Just curious, why is Iran considered to be the greatest enemy of Israel?
Because Iran is the only Muslim country that stands up for itself and other oppressed Muslims around the world. The Arab governments are a laughing stock at best, and downright duplicitous at worst. Even Pakistan, which prides itself on its military power, is known to be beholden to US/Saudi dictates.
In Bosnia, where Muslims were being massacred by the Russian-backed Serbs, it was Iran who sent a planeload of weapons in defiance of the European arms embargo. The Arabs were happy to let their European masters, er friends, 'handle' the situation.
In Kosova, again, before the Americans stepped in and the Europeans were twiddling their thumbs as Muslims were being ethnically cleansed, Iran was one of the first countries to help them. The Arabs did nothing and were content to let the Europeans and Americans 'handle' the situation.
In Gaza, the Iranians defied the Israeli/Western demand to punish the Palestinians for democratically electing Hamas. The Arabs supported the Israeli position. In fact, the Arab governments are just as much an enemy of the Palestinians as are the Israelis. More and more ordinary Arabs are starting to realize it, and it is increasing Iran's popularity in the Arab world, which is one reason for the Saudi royal tantrum.
Bottom line, Iran is striving for self-reliance and is defiant in the face of Western blackmail. The Arabs have no backbone and have lost all dignity to Israel. They are desperate to salvage some self-respect by beating their chest about Iran.
P.S. It's funny to see some Turks defending the Arabs. The Arabs hate the Turks just as much as they hate the Persians.