According to critics of Islam, Islamic terrorism is linked to the practice of divinely sanctioned warfare against apostates.
Polls taken by Saudi owned Al Arabiya and Gallup suggest moderate support for the September 11 terrorist attacks within the Islamic world, with 36% of Arabs polled by Al Arabiya saying the 9/11 attacks were morally justified, 38% disagreeing and 26% of those polled being unsure.[91] A 2008 study, produced by Gallup, found similar results with 38.6% of Muslims questioned believing the 9/11 attacks were justified.[92] Another poll conducted, in 2005 by the Fafo Foundation in the Palestinian Authority, found that 65% of respondents supported the September 11 attacks.[93]
"Allah's Apostle said, "I have been sent with the shortest expressions bearing the widest meanings, and I have been made victorious with terror (cast in the hearts of the enemy), and while I was sleeping, the keys of the treasures of the world were brought to me and put in my hand." Abu Huraira added: Allah's Apostle has left the world and now you, people, are bringing out those treasures (i.e. the Prophet did not benefit by them). Narrated in Abu Huraira.
— Sahih al-Bukhari, 4:52:220, see also Sahih Muslim, 4:1062,Sahih Muslim, 4:1063,Sahih Muslim, 4:1066,Sahih Muslim, 4:1067 and Sahih al-Bukhari, 5:59:512
Furthermore Muhammad said in another Hadith:[46]
The Prophet said, "Who is ready to kill Ka'b ibn al-Ashraf who has really hurt Allah and His Apostle?" Muhammad bin Maslama said, "O Allah's Apostle! Do you like me to kill him?" He replied in the affirmative. So, Muhammad bin Maslama went to him (i.e. Ka'b) and said, "This person (i.e. the Prophet) has put us to task and asked us for charity." Ka'b replied, "By Allah, you will get tired of him." Muhammad said to him, "We have followed him, so we dislike to leave him till we see the end of his affair." Muhammad bin Maslama went on talking to him in this way till he got the chance to kill him. Narrated Jabir bin 'Abdullah
— Sahih al-Bukhari, 4:52:270, see also Sahih al-Bukhari, 5:59:369,Sahih Muslim, 19:4436
And another Hadith:[47]
The Prophet passed by me at a place called Al-Abwa or Waddan, and was asked whether it was permissible to attack the pagan warriors at night with the probability of exposing their women and children to danger. The Prophet replied, "They (i.e. women and children) are from them (i.e. pagans)." I also heard the Prophet saying, "The institution of Hima is invalid except for Allah and His Apostle. Narrated As-Sab bin Jaththama
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Sahih al-Bukhari, 4:52:256, see also Sahih Muslim, 19:4321 Sunan Abu Dawood, 38:4390