Rex is simply stating that the world used to react to events like this differently. The code of chivalry ensured that the innocent were left alone.
The code worked with local conflicts and between neighbouring kingdoms. It doesn't work so well on a global scale.
The difficulty lies in how the world reacts to events like this. There was a time when rogue kingdoms or evil rulers were attacked, punished or killed for their misdeeds. In the modern world, that solution is more difficult to achieve.
In days of yore, the code protected the innocent from harm and allowed the guilty to be punished. With the odd exception, even the bad guys followed the code. Today's evil doesn't care who gets hurt or how much damage is caused. In short, the end justifies the means.
The conflict? Should the West, in order to rid the world of ISIS and the evil that's rife in the Middle East, react in the same or harsher manner? How does the West build concensus with China and Russia in order to stop the constant killing? The solution is obvious to all the powers, nuke the Middle East, but who wants to be the one to pull the trigger? This solution will kill a lot of people too. It's a giant, global conundrum. A planetary version of surgeons debating how much tissue to remove in order to stop the gangrene.
There isn't much of a moral dilemma, but there is a financial one. Can you harvest and use oil extracted from a nuclear wasteland?
Time will decide. How long can you poke the world with a stick before it gets fed up and definitively takes action?
The world may have acted like you think sometime in a distant forgotten past. There is nothing new in False Flag attacks carried out by the rich and powerful to incite the motion of mobs of illinformed citizens in a perferred direction. In fact it has been the standard method of steering at least since the advent of the written word. The west has obliterated much of the middle east and hundreds of other lands they had no legal bussiness inteferring in. Gangrene rules this world. No nation or group wields the stick like the USA does they are the global enforcers for the worlds banking elite, and nothing else.