The use of Force is allowed in Islam. However, Islam lays down clear guidelines as to how warfare is carried out. Killing innocent Men, Women and Children is Forbidden.
Ibn `Umar (May Allah bepleased with them) reported: Messenger of Allah (PBUH) said, “A believer continues to guard his Faith (and thus hopes for Allah’s Mercy) so long as he does not shed blood unjustly”. [Al-Bukhari]
Islam strictly forbids killing of innocents. Nobody can ever be justified in killing any innocent man, woman or child. It is indeed a grave sin. Infact, all forms of oppression are outlawed and Muslims are encouraged to help others no matter what their religion or background is.
We are commanded by Allah to lead peaceful lives and not transgress against anyone, but also to defend ourselves against oppression by “fighting against those who fight against us.”
Fight can be defensive. Such as protecting our homes, people, land and way of life. It can be Liberating, helping free others from tyranny and oppression.
Allah says in the Quran:
O you who believe! Stand out firmly for justice, as witnesses to All’h, even though it be against yourselves, or your parents, or your kin, be he rich or poor, All’h is a Better Protector to both (than you). So follow not the lusts (of your hearts), lest you may avoid justice, and if you distort your witness or refuse to give it, verily, All’h is Ever Well Acquainted with what you do [4:135]
So, Muslims are those who strive to attain justice, between themselves and with other people.
The way (of blame) is only against those who oppress men and wrongly rebel in the earth, for such there will be a painful torment. (42:42)
Islam emphasises justice, equality between race, gender and rich and poor.