Never forget that those with the power to do incredible violence against entire populations are the ones most heavily pushing the line that "violence is never, ever acceptable for any reason".

The nature of the real world is that no set of moral rules applies to every situation. Our universe is not one that deals in absolutes. Your personal moral code will be challenged with exceptional situations. Growing up is learning to deal with the fact that life always, always forces us to compromise.

A robust moral code is not one with strict, unbreakable rules applied blindly to the entire world. A robust moral code is one that guides you in exceptional situations. Morality is not law, it is making the best decision you can in any given situation.

The nature of humanity, the world, and our history is that sometimes violence is required. Sometimes the most morally correct thing you can do is take up arms and defend your people.

If someone is trying to convince you that there are absolute moral laws that apply to everyone everywhere, think very carefully about what it is they want you to believe and why. There is almost certainly a motive behind that statement.

Most importantly, one should never take moral advice as unquestioned law. Morality is something you discover for yourself, it cannot and must not be prescribed. History exists to teach us lessons like this. Read any era from any culture, learn how other people deal with moral questions in exceptional circumstances. Form your own opinions of what we've done right or wrong. There are no absolutes and morality is individual. You must find your own sense of right and wrong.