In the first place, we would like to stress that Islam is the most peaceful religion in the world. It calls upon its followers to uphold peace and security. It forbids killing and destroying mankind and animals.
Also, we would like to emphasize that offering any help to foreign invaders who launch aggressive war against the Muslim people is considered a major sin and an act of befriending the enemies of Allah, which is forbidden. This is explicitly prohibited in the Glorious Qur’an: “O ye who believe! Choose not My enemy and your enemy for friends. Do ye give them friendship when they disbelieve in that truth which hath come unto you, driving out the Messenger and you because ye believe in Allah, your Lord? If ye have come forth to strive in My way and seeking My good pleasure, (show them not friendship). Do ye show friendship unto them in secret, when I am best Aware of what ye hide and what ye proclaim? And whosoever doeth it among you, be verily hath strayed from the right way.” (Al-Mumtahanah: 1)
Dr. Sano Koutoub Moustapha, Professor of Jurisprudence and Its Principles at the International Islamic University, Malaysia, adds: “Islam is the most peaceful religion in the world. It calls upon its followers to uphold peace and security. It forbids killing and destroying mankind and animals. Therefore, it condemns all acts leading to killing or fighting among its followers or against innocent people.
On this ground, killing a Muslim or a non-Muslim for the sake of democracy or anything is considered a grave sin that all parties involved in will be punished for on the Day of Judgment. Muslims and non-Muslims should all do their best to prevent any action and ambition that leads to war, be it among Muslims or between Muslims and non-Muslims.
Those who assist directly or indirectly in killing a fellow Muslim or any human being will be equally punished on the Day of Judgment. The Prophet (peace and blessings be upon him) clearly stated that whoever contributed to the killing of a Muslim, even by half word, he or she will be severely punished in the Hereafter. What about those who provide all kinds of support to those people willing to kill Muslims or non-Muslims without any justification before Allah? May Allah protect all blood in Iraq and elsewhere.”
Moreover, Dr. `Abdul-Fatah Idrees, Professor of Comparative Fiqh at Al-Azhar and United Arab Emirates Universities, states the following: “Allah Almighty prohibited cooperation in committing sins or oppressing others. Allah Almighty says: “But help ye one another unto righteousness and pious duty. Help not one another unto sin and transgression.” (Al-Ma’idah: 2)
Therefore, those who help the invaders in their war against Muslims are staining their hands with the blood of Muslim brothers, that is to say, they help in killing their brothers by the armies of the enemy that terrorize the secure people and disturb their normal course of life.
Allah Almighty has forbidden mutual help in the course of sins and transgression. So, whoever cooperates with those aggressive transgressors is, in fact, committing a grave sin. Not only that, but he who lends them any form of support in the aggression is befriending them, and whoever befriends a kafir (disbeliever) at the expense of his Muslim brothers is similar to the kafir he befriends.”