Principle number 24 of Basic Elements of Islam: Islamic writings teach the use of pretext to initiate hostilities. The Quran devotes a lot of time complaining about people who did not support Mohammad when he first started his religion, with Allah often condemning them to torment in hell in the hereafter. The Quran is intensely intolerant of non-Muslims (source).
Mohammad was somewhat pushy and insistent with his religion, and when others felt intruded upon and protested, Mohammad took that to mean they were trying to stop Allah's holy prophet from bringing the revealed word of Allah to the world, so he was justified to fight them and destroy them as Allah's enemies. This is a demonstration of the principle of pretext.
Non-Muslims of the world need urgently to become aware of this principle. Of all the ideas in the Islamic collection, this is the most dangerous to the West because it removes our natural self-preserving defenses. The use of pretext tends to make the West defenseless against Islamic encroachments. And it tends to make the West confused about how to respond to violent Muslim reactions.
The use of pretext means you need only the barest excuse to begin hostilities. It means actually looking for an excuse, and even trying to provoke others into striking the first blow ("starting" the hostilities).
If the only way to get to Paradise is dying while fighting for Islam, you need hostilities. And if it is your holy duty to make all governments use Sharia law, you need to conquer non-Islamic governments. But you don't really want to look like the aggressor. Appearances count. All throughout the Quran, Mohammad tries to justify his aggression as defending Islam.
The Quran repeats 91 times that followers of Islam should use Mohammad as a model and imitate him. So Muslims the world over try to find or create grievances, so they can recruit new warriors, so they can get a holy war started, so they can fight and die in Allah's cause.
And because of the rise of multiculturalism (respect for all other cultures) in the West, the use of pretext is very effective against people who are unfamiliar with Islam. Many Westerners are concerned that al Qaeda is angry at the West for having troops in Saudi Arabia, for example. That's merely a pretext. They want all non-Muslims out of the Middle East. Then they say they will cease hostilities. It is a ridiculous and impossible goal, so they are justified in permanent war against the West to "defend" Islam.
It's surprising that so many Westerners accept this particular pretext because it flies in the face of a fundamental Western principle: Equality. What Osama bin Laden is saying is, "infidels are so undeserving, their very presence somewhere in Arabia defiles the entire country." Wow. What does that say about the non-Muslims?
Why doesn't this kind of racism or prejudice or infidelphobia (or whatever you want to call it) outrage more Westerners? Instead, many think we ought to pull out of the Middle East so we stop offending these poor Muslims.
The principle of pretext means you try to provoke a hostile reaction and then use the hostile reaction as a reason to escalate hostilities. It's the same method schoolyard bullies have used for thousands of years.