Why use a hypothetical when the world is full of real examples? The Syrian civil war may be a great place to examine our values. The current crisis has been on-going for 5 years with ever-increasing misery on the Syrian people. The choices and possible consequences are:

1. Join with China and Russia in supporting the Assad government to crush the rebels and ISIS decisively. This action will definitely bring order to the war-torn region. Syrians will be able to return home from the far-flung refugee camps around the world. Of course, those suspected of rebel activities will be summarily executed in the thousands, but thousands more will be able to lead a stable life, once Assad government re-establishes order through fear.

2. Support the rebels in opposition to Russia and China. This will escalate the conflict even more. There is a potential for direct conflict with Russia and China resulting in direct harm to our interests. The conflict will likely continue for decades (taking the Vietnam War as paradigm) with concurrent miseries all around. Even if the rebel faction triumphs, the establishment of a stable government will take even more years, further draining our resources. The shrills of nationalism will continue to escalate in our societies, if we continue to bear the cost of the conflict, which may destabilize our societies. But if the West is true to their principles of "democracy," "rule of law," "human rights," then this will have to be the principled decision.

3. Refuse to intervene following the principles of international law, as set by the Peace of Westphalia. This is also a principled approach, if one is an adamant legalist of the international sort.