Not, as noted before, excuses.
Where to f*ing start...
Well, first there were the Crusades. :-) [No, that's important!]
The Brits had most of the Middle East as part of the Em-pah up until WWII. One of the things they did was the Balfour Declaration, which among other things was the first notion of the State of Israel. That was in 1917, and what they were trying to do was get Jewish support in WWI. The Arabs... reacted badly :-) Some Jews tried to move to Palestine, purchasing land and homes there, and the Arabs killed some and ran most of the rest out. The Brits tried to protect them, but failed.
Then came WWII and the "final solution". Note that, at the time, the U.S. was only faintly less anti-Semitic than the Nazis; at one point a shipload of Jewish refugees was trying to find a place to land, and nobody would accept them, especially the U.S. -- after the war, embarrassed by the treatment the Jews had gotten and their tacit acceptance of same, the Allies decided to implement the Balfour Declaration and set up the State of Israel in Palestine.
As far as the Arabs were concerned this was just an extension of the Crusades. The Crusaders set up governments in the Holy Land, with taxes and the whole bit; from the Arab point of view, Israel is just the latest in a succession of Crusader States. The Arab states in the vicinity told the Arabs living in Palestine to get out, so they could have a clear field to wipe out the Jews and eliminate Israel. They failed miserably.
The Palestinians became an embarrassment. The Arab states couldn't let them go home; there was every possibility that the Jews would live up to their declarations of religious freedom and civil rights, and that would eliminate the Arabs' justification for wiping Israel out. On the other hand, the Arab states couldn't accept the Palestinians themselves; for one thing, there were too many of them for comfort, and for another, if Palestinians disappeared as a people, there would again be little justification for hostility toward Israel. The Palestinians sat in their camps, broke, homeless, and hopeless, and festered. One of the reasons the Palestinians are so nasty is that they are simply irrelevant to the rest of the conflict, except as symbols -- heads on poles to excite the rest of the faithful -- and they know it.
Along about this time the mullahs [Islamic equivalent of a parish priest, more or less] noticed that Western ways were starting to corrupt the young. Civil rights for women, beard-shaving, and secular authority were creeping up on their powers and privileges. The mullah of a mosque in a poor town in Islamic lands is the final authority on most anything; many of them didn't want to give that up, and they began preaching "Islamic Fundamentalism", a direct analogue of Christian Fundamentalism here and in Europe.
In Iran, then called "Persia", the Soviet Union was sponsoring a fairly successful Socialist reform. The CIA went in, eliminated the Socialists [with substantial help from the locals, not all of whom liked the idea] and set the Pahlevis on the throne of Iran. The Pahlevis were "enlightened despots", who ruled by decree and started forcing Westernization -- cars, women's dress, TV, and all the other things Ashton bemoans :-) The secular government of Iran simply ignored the mullahs and what might be called the Church authority. This threatened the Iranian Islamic clerics' powers and privileges, and they reacted with hostility, and began picking up Islamic Fundamentalism.
Then the United States started seriously extracting oil from the region, especially Saudi Arabia, and that started really bringing Westernization to the Islamic world. How ya gonna keep 'em down on the oasis after they've seen Houston? :-) Islamic Fundamentalism got a boost. The Sons of Ibn Saud [who aren't fundamentally any nicer than the Shah] boosted it further, in order to maintain their own power in Saudi Arabia. Westerners in Saudi Arabia had [and still have] to live in compounds and obey Islamic customs if they venture out; this makes it harder for the U.S. oil companies [who paid for the surveys that found the oil, the wells to extract it, and and and] to simply assert posession. The Saudis also started supporting Fundamentalists elsewhere, and they had lots of oil income to do that with.
Meanwhile Israel was being successful, with the highest standard of living in the region. That was a horrid affront, and the Arab states were properly affronted. Since the Fundamentalists had as their basic thesis that Westernization was bad, and the Jews were importers of Westernization and infidels to boot, they preached that Israel had to be eliminated -- which resonated nicely with the perception among non-Fundamentalists of Israel as a Crusader State.
I don't think anyone here is unimaginative enough to be unable to figure out the rest of it; the details really don't matter. Then along came Osama bin Ladin. Up to that time, things were moving; glacially slowly, but moving. bin Ladin is primarily an agitpropper, a Hitler; he makes great speeches that make Arabs feel good about themselves and their power. If he believes anything it isn't known, but he makes a great show of supporting Fundamentalism, because he thinks [so far quite correctly] that by doing so he can get the Fundamentalists behind him. His goal is to be Saladin, 2000 model -- the Maximum Ruler of the World Islamic State.
There's lots more, but that's enough here.