"reading the Koran is precisely the wrong way to go about understanding "what's happening in our world." That's because the Koran is:
Complex and contradictory. Contradictions in the text have been studied and reconciled over the centuries through extensive scholarly study. Some verses have been abrogated and replaced by others with contrary meanings. For example, verse 9:5 commands Muslims not to slay pagans until the sacred months have passed and verse 9:36 tells Muslims to fight pagans during those same months. The casual reader has no idea which of these is operational. (In fact, the latter is.)
Static: An unchanging holy scripture cannot account for change over time. If the Koran causes terrorism, then how does one explain the 1960s, when militant Islamic violence barely existed? The Koran was the same text then as now. More broadly, over a period of 14 centuries, Muslims have been inspired by the Koran to act in ways aggressive and passive, pious and not, tolerant and not. Logic demands that one look elsewhere than an immutable text to account for such shifts.
Partial: Holy books have vast importance but do not create the immediate context of action. Reading the Bible in isolation gives limited insight into the range of Jewish and Christian experiences over the millennia; likewise, Muslims have read the Koran differently over time. The admonishment for female modesty meant one thing to Egyptian feminists in the 1920s and another to their descendants today. Then, head coverings represented oppression and exclusion from public life. Today, in the words of a British newspaper headline, "Veiled is beautiful." Then, the head-covering signaled a woman not being a full human being; now, in the words of an editor at a fashion magazine, the head-covering "tells you, you're a woman. You have to be treated as an independent mind." Reading the Koran in isolation misses this unpredictable evolution. In brief, the Koran is not a history book." -- Daniel Pipes
verse 9.5: So when the sacred months have passed away, then slay the idolaters wherever you find them, and take them captives and besiege them and lie in wait for them in every ambush, then if they repent and keep up prayer and pay the poor-rate, leave their way free to them; surely Allah is Forgiving, Merciful.
verse 9.36: Surely the number of months with Allah is twelve months in Allah's ordinance since the day when He created the heavens and the earth, of these four being sacred; that is the right reckoning; therefore be not unjust to yourselves regarding them, and fight the polytheists all together as they fight you all together; and know that Allah is with those who guard (against evil).
I see no contradiction between the plain text of the two verses. In the first is a command to fight the "polytheists" (and I assume a Catholic who believes in the Trinity would qualify) after the "sacred months". The passage does not prohibit fighting them during the months, just mandates fighting after the months. The second verse tells Muslims to maintain unity in the fight.
Islamic doctrine is to feign peaceful intentions while weak, and strike as soon as the Muslims are strong. The Islamists didn't have much in the way of funding until OPEC managed to get oil prices up in the 70's
Translation: "Outsiders cannot understand our sacred writings. So stop pointing out embarassing passages which reveal our true intentions, and just listen to our PR"