The Saudis are not happy with the links between terrorists inside Saudi Arabia, and Iraqi Sunni Arabs. The Saudis have told the Iraqi Sunni Arabs that the Sunni Arab nations in the regions will not bail them out, and that they must make peace with the Shia Arab majority. Many Sunni Arabs, throughout the region, do not agree with this. But they are a small minority. Most Sunni Arabs are appalled at the body count the Sunni Arab terrorists have created in Iraq. While most of the dead are Shia Arabs, a growing number are Sunni Arabs, killed either by the suicide bombers, or by Shia Arab death squads looking for revenge. While most Sunni Arabs would like to see Sunni Arabs running Iraq, there was revulsion at Saddam Husseins methods, and even greater distaste for the subsequent mayhem by his followers.Source
Saudi investigators also discovered that there were also terrorist training camps in northern Yemen, an area controlled by Shia Arab tribes that are hostile to the Sunni Arab Yemeni government. The connection with both Syria and Yemen is Iran, which subsidizes Syria, and supports the Shia tribes in Yemen. Saudi Arabia sees Iran has its primary enemy, not the Shia form of Islam (which most Iranians, who are not Arabs, and most Iraqis, who are, follow). The Iranians take advantage of the fact that al Qaeda has become the place to go if you believe in a very conservative version of Islam, and are certain that the sorry state of the Moslem world is all due to a plot by evil infidels (non-Moslems, especially Christians, Hindus and Jews) to destroy Islam. Even though al Qaeda considers Shia Moslems to be heretics, and worthy of persecution and execution, the Iranians are willing to cooperate if it will lead to problems for the Sunni rulers of Saudi Arabia. Politics, ethnic antagonisms and religious beliefs produce a strange brew in the Middle East.
If the US stays in Iraq--a key middle east location, geostrategically--long enough to prevent outright war between Iran and the Sunni states, it may be possible for the hotbed of violence and terrorism to settle substantially. Many uninformed folks blame George Bush for the violence and terror in the mideast. Sometimes they do this from ignorance, and sometimes from disingenuous animosity. Either way, it makes them superfluous, at best, to the real problems that are occurring.