The main argument terrorists use is this verse: whoever then acts aggressively against you, inflict injury on him according to the injury he has inflicted on you (2:194). Based on that, they justify the murdering of civilians since that the enemy is murdering Muslim civilians (Palestine and the blockade on Iraq which resulted in more than 1.5 million deaths among children due to the lack of food and medical supplies, but post 9-11 you can add to that the American invasion of Afghanistan and Iraq).
Another argument is.... well let me first say : There are two conflicting Hadiths, in one Muhammad says that killing non-warriors - such as women and children- is prohibited; and in the other one Muhammad was asked about raiding in night when the attacker can't see well leading to the killing of women and children, Muhammad responded: "They are among them (the enemy)". Muslim scholars solved this contradiction by saying that the deliberate targeting of women and children is prohibited, but if the attacker can't distinguish them from the warriors then it's OK. Terrorists and their apologists actually used this argument for even justifying the murdering of Muslims in their attacks. That's why they don't care that the majority of the victims of attacks against American forces in Iraq are actually Muslims.
+1
^ Eloquently put. A third rationale one commonly hears from the lips of ululating beardos for sending the godless into the arms of God uninvited is that the taxpayer faciliates aggression against Islam by filling the coffers of the treasury out of which the defence budget comes. Right from Bin Laden's lips that. It makes no difference that withholding one's taxes is a penal offence or that a slice of the revenue so generated is diverted to foreign aid to feed the basket cases of failed Islamic states. Their dirt poor family who subsist on UN food rations included. But who said logical consistency was ever the strong suit of the towelheads?
Barakallahu Feek
+1
I have little doubt that radical Muslims who support terrorism strongly believe that
they are the better Muslims, and that those who oppose jihad/terrorism are wimps who just want to appease the West and continue living in luxury. What motivates the radicals most is a combination of politics and religion. They use perceived grievances to attract Muslims to their cause, and then inject the love of God in them and the love of paradise, 72 virgins etc etc. Young men also enjoy having a purpose to their life. It gives them a sense of power.
As Salim Munqith has mentioned above, there is enough in the Quran and Hadith to justify terrorism, so the radicals find it relatively easy to indoctrinate young Muslims. The (so-called) moderates are fighting a losing battle unless they consciously agree that
the Quran and Hadith are irrelevant in today's age. And that is something they are not prepared to do, except for a tiny minority of Muslims.