If there is any doubt that he believed that the forbidden is sometimes necessary, it should be put to rest by an incident in which Muhammad's men warned him that a planned night raid against an enemy camp would mean that women and children would be killed. He merely replied %u201Cthey are of them,%u201D meaning the men.
This is the slippery slope that is opened by the sanction of holy war. What starts out as the perception of a noble cause of self-defense against a supposed threat gradually devolves into a "let Allah sort them out" campaign through a series of logical steps that are ultimately justified by the sublime goal of Islamic rule.
Islam is not intended to co-exist as an equal with other religions. It is to be the dominant religion, with Sharia as the supreme law. Islamic rule is to be extended to the ends of the earth, and resistance is to be dealt with by any means necessary.
Apologists in the West often shrug off the Qur'an's many verses of violence by saying that they are only relevant in a %u201Ctime of war.%u201D
To this, Islamic terrorists would agree. They are at war.