The United Arab Republic included Egypt and Syria - they tried to pull Yemen in and at one point Libya proposed to join Egypt.
Suppose that after the 1968 war, Nasser (one of the only Arab leaders who ever achieved any popularity) sees a cardiologist and is put on a healthy diet exercise regime as well as blood pressure meds.
He campaigns around the Arab world and is met by larger and larger crowds.
After the 1973 war and oil embargo, the light bulb goes on. There emerges enormous public pressure for an Arab Super State running from the Atlantic Ocean to Iran and from Turkey to the Red Sea. The unifying principle is Arab nationalism so that Christians and Shiites are welcome and enthusiastic supporters of the new state.
Countries fall like dominoes (the Saudi regime resists but is overwhelmed by a combination of internal and external forces) and a unified federation is created which now controls more than half the world's oil reserves. The spigots are immediately ratcheted back and the Western economies take a nosedive.
The new mega-state demands a permanent seat on the UN Security Council, a return of Israel to pre-1968 borders, authorization to acquire nuclear weapons, and withdrawal of all Western military forces from the area. Some of these demands (the Security Council seat, the Israeli borders) are granted in an effort to save Western economies from the dire effects of an oil cut off. This success enhances the regimes popularity and allows for more centralization. And there is plenty of moolah to spread around with the oil price being supported at a high level.
Where do we go from here? How would "Arab Unity" have effected the last 50 years?