In this article, I bring up more than usual quotes from the Quran in order to try to avoid my own opinion about the matter. I ask Allah to stand by me in this attempt.
In difficult times shows up who is who and what is the example or pattern that can be followed. Until the trouble hasn't struck, we could only see examples that suggested the rise and dominance of the ego. Along with the unprecedented concentration of capital, we have experienced the mass appearance of misery. We, Muslims have also committed a sin in this process. Muslim capital and the unprincipled betrayal of their leaders have contributed to the enrichment of the few and the impoverishment of many. So, we cooperated in bad things, even if we were only suspecting those were bad. This will not give excuse for anyone:
But most of them follow nothing but fancy: truly fancy can be of no avail against truth. Verily Allah is well aware of all that they do. (Quran 10:36)
And pursue not that of which thou hast no knowledge; for every act of hearing, or of seeing or of (feeling in) the heart will be enquired into (on the Day of Reckoning). (Quran 17:36)
Nay, man will be evidence against himself, (Quran 75:14)
"On the Day when their tongues, their hands, and their feet will bear witness against them as to their actions." It is not what a man says about himself, or what others say of him, that determines judgment about him. It is what he is in himself. His own personality betrays him or commends him.
Now the principles are rearranged and the humanity is forced to follow new examples (insha Allah). It is not important if one considers him/herself to be important, but becomes important only if he/she is important to others, too. If we follow this set of value, harmony will be created between our hearts. The question arises here: can there be harmony and cooperation between Muslim and non-Muslim?
It may be that Allah will grant love (and friendship) between you and those whom ye (now) hold as enemies. For Allah has power (over all things); And Allah is Oft-Forgiving, Most Merciful. (Quran 60:7)
Apparent religious hatred or enmity or persecution may be due to ignorance or over-zeal in a soul, which Allah will forgive and use eventually in His service, as happened in the case of Hadhrat 'Umar, who was a different man before and after his conversion.
Allah forbids you not, with regard to those who fight you not for (your) Faith nor drive you out of your homes, from dealing kindly and justly with them: for Allah loveth those who are just. (Quran 60:8)
Even with Unbelievers, unless they are rampant and out to destroy us and our Faith, we should deal kindly and equitably, as is shown by our holy Prophet's own example.
…Help ye one another in righteousness and piety, but help ye not one another in sin and rancor: fear Allah, for Allah is strict in punishment. (Quran 5:2)
We've got two answers above. A historical and a Divine answer. Historically, it makes no difference that I follow the example of Mecca where Muslims were in a minority under the supremacy of Qureish (see Abu Talib) or the example of Medina where the majority were Muslim; in building a constructive set of value, understanding, harmony and cooperation is needed between Muslims and non-Muslims.
Remember that Muslim and non-Muslim are just words. And behind the word can hide many contents. It may be that a non-Muslim follows Islamic values and a Muslim does not.
The other is the Divine Order, which elevates this principle to the level of revelation.
I'm an idealist and I deeply believe inside that there are many good goals to realize together. It's just a belief, an assumption, because my eyes see something else. I see the good yet, but the man who struggles for it, less and less. I hope my eyesight is wrong.