I think that they make themselves abundantly clear.
They are motivated by ideology. They see the primacy of Allah over the world and the importance of man to obey scripture.
They think that the only way to maintain pure Islamic values is through reversion to a way of life more in accordance too 7th Century Arabia. Modernity is against God to these individuals. Democracy and liberty and political systems invented by man that place the individual ahead of God, these systems are not compatible with their belief that all must submit too God.
Now this belief system does not infer terrorism, there can be peaceful fundamentalists who live their own lives strictly according to scripture but that is not how these particular groups operate. They extend the religious into a political system, which is Islamism. By building a system built up on literalism and rejection of un-Islamic concepts and material goods man is living the right way. A relatively decent example of such a system is Afghanistan under the Taliban, once siezing control after a civil war they were able to govern the country the way that they (the ruling class of theocrats) desired; purging of outside influence like television, enforcing modesty upon women, destroying idols such as the Bamiyan Buddha's, outlawing music and sports. They also took to refining the legal system, bringing back the amputations, stonings and public executions for common crimes like theft, adultery and apostacy.
Okay so now they enforce their glorious Islamist paridise on a country ravaged by war that is ripe for the picking by a cadre of totalitarians, all fine and good since it is restricted to a single country. Well here is where there terrorists come in.
Al Qaeda, Jeemah Islamya, Hamas, MILF etc. they are all Islamist groups that employ terrorism to achieve their ends, now it is not particularly surprising that they are all from areas of war and civil strife (with the exception of Al Qaeda which is considered an international group but is such a broad brush it covers an entire ideology ~ it is inconcequential if Osama bin Laden is alive or dead because his past actions inspire others to their own, the entire ideology of taking a war to the percieved "opressors of Islam" and striking them into submission until their political system can be established and expand can be a very broad thing and it encompasses many groups that are connected by individuals - like a Jihad version of the Kevin Bacon game - but without a direct operational heirachy plotting and planning every last attack and its details) ~ that is where they can tap the most popular support and develop a base of operations. These groups will violently fight their enemies and the civilian populations of their enemies by any means neccessary; we all know the story we see it every day on the news, beheadings, suicide bombers, "gunmen" - but on the flipside they also start to establish government (on various levels), and these governments are built on the same Islamist ideology (but more often than not to a much lesser degree than the Taliban). Now the nationalist movements with a quasi-Islamist component to them are nasty situations and that is more tied up with domestic conflicts and settling them, with these I think that peoples own personal ideas influence how they feel about them, for instance Hamas is being given legitimacy by European governments who are begining to engage them for negotiaton; some may see that as a positive, I do not because Hamas as a movement is built on two things; firstly the 'liberation' of 'Palestine', now when Hamas talks about Palestine they do not mean the West Bank, Gaza and Jerusalem ~ they mean
everything from Jordan to the Mediteranian ~ in their own words "Driving the Jews into the Sea", their own propaganda proudly boasts about killing Israeli civilians ~ justify attacks against Pregnant women on the basis that an unborn child is a future soldier, introduce selective views of their holy texts to justify their large scale plans of ethnic cleansing (which are fantasy by their means but serious in their minds). But secondly they are Islamist; I think that their charter lays out pretty clearly their desire when it comes to governance and position in the world.
"Israel will exist and will continue to exist until Islam will obliterate it, just as it obliterated others before it."
"The Islamic Resistance Movement believes that the land of Palestine is an Islamic Waqf [a religious endowment, as delineated by Islamic law] consecrated for future Moslem generations until Judgement Day. It, or any part of it, should not be squandered: it, or any part of it, should not be given up. "
"There is no solution for the Palestinian question except through Jihad. Initiatives, proposals and international conferences are all a waste of time and vain endeavors."
"After Palestine, the Zionists aspire to expand from the Nile to the Euphrates. When they will have digested the region they overtook, they will aspire to further expansion, and so on. Their plan is embodied in the 'Protocols of the Elders of Zion', and their present conduct is the best proof of what we are saying."
"Moreover, if the links have been distant from each other and if obstacles, placed by those who are the lackeys of Zionism in the way of the fighters obstructed the continuation of the struggle, the Islamic Resistance Movement aspires to the realisation of Allah's promise, no matter how long that should take. The Prophet, Allah bless him and grant him salvation, has said:
"'The Day of Judgement will not come about until Moslems fight the Jews (killing the Jews), when the Jew will hide behind stones and trees. The stones and trees will say O Moslems, O Abdulla, there is a Jew behind me, come and kill him. Only the Gharkad tree, (evidently a certain kind of tree) would not do that because it is one of the trees of the Jews.' (related by al-Bukhari and Moslem)."
"Allah is its target, the Prophet is its model, the Koran its constitution: Jihad is its path and death for the sake of Allah is the loftiest of its wishes."
(
http://www.mideastweb.org/hamas.htm)
Now they are a
few quotes; read the whole thing to get context please, but it may give a bit of insight into their motivations, a purely Islamic state existing in "Palestine". So it is an Islamist Nationalist movement with rooted goals. Now Al Qaeda which does derive it's ideology from a different tradition of thought is not so much dedicated to pure Islamic states in the Middle East exclusively (replacing the corrupt secular dictators, the stalwarts of failed Pan-Arab Nationalism and the corrupt and "un-Islamic" regimes propped up by oil and America in the Gulf). They map their plans onto a global scale and they believe with full conviction and aspiration that one day in the future the entire world will live under Islamist governance, a truly global Ummah (think of an Islamic Christendom). Now that is a long term goal, and as such the groups set incremental goals; so start at square 1 to restore the Islamic world to it's former glory, the way they figure that can be done is by returning to the ways of the past and establishing a powerful unified nation; and where can such an entity be forged? the Middle East; so if they go about causing trouble for US client states and their leaders, subverting unpopular dictators and setting the seeds of revolution or destabalising the regimes they may be able to get into power either through coups, popular revolutions or sparking civil wars from which a powerful and unified Islamist (remember political ideology) group may emerge. If the right regimes are toppled then the balance of power may favour them, enabling a sort of domino effect. The end product of their supposed revolutions would be the creation of a united set of Islamist nations; a pan-Islamic superstate. Now different groups in different regions do aspire for such a creation; JI in Indonesia is one, it is a SE Asian terror group, their long term/big picture goal is the formation of a state stretching from Malaysia too Mindanao. The idea of creating an Islamist superpower also goes to the ressurection of the Caliphate; the leadership system that Al Qaeda and related groups see was the greatest workable system of Islamic governance. Once reestablished and entrenched the Caliphate may extend furthur than the past and all of humanity may finally get to know the feeling of living under Islamist governance with strict sharia law. A united humanity existing to revere God and live in the 'right' way. Sort of makes me glad that they probably will never achieve their ends ~ a world without science, art, free thought and discovery, sport, crushing of the individual, a homogenous mass of subjegated beings covering the planet without individual aspiration. The logical progression of what the very hardcore Islamist system that "Al Qaeda" advocates on a global level; those guys make Khomeni look moderate.
Long story short if you want to understand Islamism (which is bigger than 'Al Qaeda', the idea of a centralised command and control structure for this ideology would seem to be a mistake from what I have read)
I am sure that people have read their own books on the organisations and I am sure that they do give an overview; some good and some bad; I think that Daniel Pipes writings are usefull reading, but of course read other books and see other media to get a fuller picture.
I am just brushing over my understanding in a rapid and haphazard manner, but the point is that these groups and the motivation for their violence is not rooted in any single injustice or correctable ill in the world. It is an entire worldview that draws support from certain injustices and manipulates passions about them too it's own end (and yes Iraq probably does drive some support for Islamism among certain groups of Muslims ~ but no more than the presence of US troops in Saudi Arabia all through the 1990's, the massacring of Muslims in the Balkans, the Palestinians and their 60 year refugees, Islamophobia etc. ~ it is a symptom of the shithouse regimes of the region, the lack of any real peaceful avenues of political expression against dictatorial regimes, a free and democratic Iraq would in the long term help the region immensely and will do more good in marginalising Islamists from the mainstream populations than any number of reactive steps, piss weak concessions of western guilt or sitting from affar politely asking the dictators too introduce their own democratic reforms as they see fit in exchange for trade deals; the change comes from the people, they have been kept down for far too long and when it comes it would be better for all if it supported the emergence free nations that can engage with the rest of the world with trade, international cooperation and progression rather than the retrograde shackles of Islamism that would be severely detrimental too world peace and the cause of individual human liberty abroad.
I make it clear that in my mind the 'fault' of 9/11 does not rest on any one administration or individual. Mistakes were made before hand, problems that can still happen and cannot be rectified short of becoming a police state and others that just havent been done because there wasn't enough money or enough motivation. "Evil-dooers", "violent extremists", "freedom-haters", "hate us for who we are" ~ these are all labels that dance around the enemy; radical Islamism. By deliberately using such vague terminology and declaring a "War on Terror" I fear that the Bush administration has made long term resistence to the threat more dificult, how the hell are people supposed to give long term (years leading into decades) of support for a war against a phantom enemy that their leaders will not identify out of politeness. Properly defining the problem; seperating it from Islam the religion; marginalising it - that is by far the best way to combat anti-Islamic sentiment, rather than the ever so vague definitions that make people think that "Islam is the enemy". The latest moves to recast the fight as a war against "violent extremists" is one more example of this shabby, shabby communication to the public and the world at large.
I would also like too recomend 'Inside Al Qaeda' by Rohan Gunaratna ~ it is a really great reference book.