Does Islam require the Muslims to act like an army?
The Qur’an addresses all aspects of human life including warfare. To take issue with the Holy Qur’an for bringing morality to war—absent in other religious scriptures, and something the West finally addressed more than 1,200 years after the advent of Islam —is unwarranted.
Wherever the Qur’an permits fighting, it does so only for defensive purposes. Muslims are advised to resort to patience, prayer and even emigration to avoid war and bloodshed. But if fighting is the only option, God commands:
And fight in the cause of Allah against those who fight against you, but do not transgress. Surely, Allah loves not the transgressors. 
And if they incline towards peace, incline thou also towards it, and put thy trust in Allah. 
Prophet Muhammad enacted advanced rules of war, forbidding mutilation, forbidding civilian attacks, etc. The Qur’an even commands Muslims to fight on behalf of other faiths to champion universal religious freedom. Islam does not allow pre-emptive attacks, and as explained in the above verses, implores Muslims to be ever inclined towards peace.
 The Hague Conventions of 1899 and 1907, coupled with the Geneva Conventions, constitute the first attempt to regulate warfare from a moral perspective in secular international law.
 Qur’an 2:191.
 Qur’an 8:62.