Defensive warfare in Islam

Muhammad's messages began to change in character. Early in his
career a group of twelve converts to Islam from the Khazraj tribe of the city
of the Medina gathered with Muhammad in the city of Al-'Aqaba, made
what is known as the first covenant of 'Aqaba: a pledge of fealty to the
Prophet of Islam. One of them explained: "We gave allegiance to the apostle that we would associate nothing with God, not steal, not commit fornication, not kill our offspring, not slander our neighbor, not disobey him in
what was right; if we fulfilled this paradise would be ours; and if we committed any of those sins we should be punished in this world and this would
serve as expiation; if the sin was concealed until the Day of Resurrection,
then it would be for God to decide whether to punish or to forgive."14
There was nothing in this pledge about warring for Islam. But a year
later, around the year 622, that was to change. Originally, explained Ibn
Ishaq, "the apostle had not been given permission to fight or allowed to shed
blood He had simply been ordered to call men to God and to endure
insult and forgive the ignorant. The Quraysh had persecuted his followers,
seducing some from their religion, and exiling others from their country.
They had to choose whether to give up their religion, be maltreated at
home, or to flee the country, some to Abyssinia, others to Medina."
But now the time for forgiveness was over:
When Quraysh became insolent towards God and rejected His
gracious purpose, accused His prophet of lying, and ill treated
and exiled those who served Him and proclaimed His unity,
believed in His prophet, and held fast to His religion, He gave
permission to His apostle to fight and to protect himself against
those who wronged them and treated them badly.15
Then Ibn Ishaq explains the progression of Qur'anic revelation about warfare. First, he explains, Allah allowed Muslims to wage defensive warfare:
Assuredly God will help those who help Him. God is Almighty.
Those who if we make them strong in the land will establish
prayer, pay the poor-tax, enjoin kindness, and forbid iniquity.

THE TRUTH ABOUT MUHAMMAD
To God belongs the end of matters.16
 The meaning is: "I have
allowed them to fight only because they have been unjustly
treated while their sole offence against men has been that they
worship God. When they are in the ascendant they will establish prayer, pay the poor-tax, enjoin kindness, and forbid iniquity, i.e. the Prophet and his companions all of them."17
"When they are in the ascendant," in other words, they will establish an
Islamic state, in which Muslims will pray regularly, pay the poor-tax
(zakat), and institute Islamic laws ("forbid iniquity"). But that was not
Allah's last word on the circumstances in which Muslims should fight:
Then God sent down to him: "Fight them so that there be no more
seduction," i.e., until no believer is seduced from his religion. "And the
religion is God's," i.e., until God alone is worshipped.18
The Qur'an verse Ibn Ishaq quotes here (2:193) commands much more
than defensive warfare: Muslims must fight until "the religion is God's" —
that is, until Allah alone is worshipped. Later Islamic law, based on statements of Muhammad, would offer non-Muslims three options: conversion
to Islam, subjugation as inferiors under Islamic law, or warfare.

14. Ibid., 199.
15. Ibid., 212-213.
16. Quran 22:39-40.
17. Ibnlshaq, 212-213.
18. Qur'an 2:193, Ibn Ishaq, 212-213.

The followers of Muhammad during his lifetime are known as his
Companions. The Companions fall into two groups: al-Muhajiroun,
or the emigrants from Mecca, and al-Ansar (helpers), the inhabitants
of Medina who took in those emigrants after the Muslims' flight
(hijra) from Mecca to Medina.'The Aws and Khazraj were two
Ansari tribes.

"Fight in the name of Allah and in the way of Allah. Fight against
those who disbelieve in Allah. Make a holy war, do not embezzle the
spoils; do not break your pledge; and do not mutilate (the dead) bodies; do not kill the children. When you meet your enemies who are
polytheists, invite them to three courses of action. If they respond to
any one of these, you also accept it and withhold yourself from doing
them any harm. Invite them to (accept) Islam; if they respond to you,
accept it from them and desist from fighting against them If they
refuse to accept Islam, demand from them the Jizya. If they agree to
pay, accept it from them and hold off your hands. If they refuse to pay
the tax, seek Allah's help and fight them." Muslim, book 19, no. 4294