VVar

There is a time for war. Generally it begins as a rebellion or as self-defense. Such as the military conflicts since the creation of Israel. Although the Israelis are some of the most militant people in the world, they were forced into this as a defense against the invasion and conflicts with other Arabic nations. Others, such as wars for independence can be justified as well.
It isn't morally right and just but it is generally necessary. Most Americans berate the war with Iraq and Afghanistan, yet could America maintain a moral code with all of the abuse and suffering in these countries? But, America and other developed nations can't even claim a full moral code after continuous conflicts in Uganda, Rwanda, DRC, and other countries who had citizens abused. In these areas, America did nothing to stop the violence, so they can't justify taking actions in Iraq. 

During genocides, discrimination, or abuse against citizens by corrupt government, a civil war or another power intervening should be necessary. A government ceases to govern when it purposefully and repeatedly harms its citizens. For this, action must be taken or the government will continue to take advantage of the situation.

Non-violent protests or Succession are valid actions to take under these circumstances. However, non-violent protests generally end in the bloodshed of innocents and don't always accomplish the task. Succession is a great way to separate opposing political or ethnic groups in a country. Yet, this might lead to further conflict. Peaceful succession can occur as in Pakistan and India, but then the countries are forever rivals and hate one another. Or the succession may fail, such as the American Civil War, and if it does, then the situation will take years or never to resolve itself.