Wa `alaykum as-salamu wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother in Islam, thanks a lot for your question, which reflects your care to have a clear view of the teachings of Islam. Allah commands Muslims to refer to knowledgeable people to beocme well acquainted with the teachings of Islam in all aspects of life.
Islam does not allow oppression or injustice perpetrated against Muslims or non-Muslims. Muslims are required to be united against oppression and to restore our occupied lands. In such awkward times facing Muslims everywhere, especially the demolition of parts of Al-Aqsa Mosque by the Israelis, we should back each other, forget about our differences, look for all possible legal means to restore our lands, and stand against oppression.
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states the following:
As Muslims we need to be united in standing against oppression and injustice; we need to be united against those who occupy our lands, oppress us, and take away our God-given rights. However, we need to use only means sanctioned by the Shari`ah; we are not to commit bloodshed which is clearly forbidden; Islam does not allow anarchy and lawlessness. We have therefore no other way than uniting and acting according to the rules established by the Shari`ah; otherwise, we will not be different from those who are oppressing us.
As for the issue of reacting to those who insult Allah and His Messenger, we must never play into their hands by reacting violently, for that is exactly what they are expecting us to do. We must respond to them by using peaceful means and methods. We have lessons in the Prophet (peace and blessings be upon him) who turned his enemies into friends by responding to them peacefully.