Death and taxes are always with us, and so are arguments about whether nations ever have the right or duty to intervene in the affairs of others. The case for "humanitarian intervention," under a variety of names, has been asserted at least since the great powers threw their weight behind Greece's struggle for independence in the 1820s, but in its modern form was developed during the Wars of the Yugoslav Succession, when it appeared to many that armed force was the only way to end terrible atrocities. More recently, the U.N. has adopted as a norm of international affairs the "responsibility to protect," which contemplates the possibility of armed intervention when a state shows itself unable or unwilling to prevent grave human rights abuses.
The war in Libya has opened up the can of worms once more, with those on one side arguing that international forces can prevent or end great wrongs, while others assert that intervention is based on the inconsistent application of fuzzy principles and amounts to little more than imperialism dressed in a cloak of bleeding-heart piety.
This debate won't be settled even if next year Libya looks like a North African version of Kent or Kansas, which it won't. But we know enough about humanitarian intervention by now to reach some conclusions about what it means in practice.
First, it will indeed be applied selectively. There are leaders in the world at least as unpleasant as Muammar Gaddafi who sleep easily abed each night. In Bahrain, Yemen and Syria, peaceful protesters have been killed recently without anyone's arguing for a NATO mission to be dispatched. The standard objection to this inconsistency is to say, "Just because you can't save everyone doesn't mean you shouldn't save someone." But although this line is flopped down as if it were the ace of trumps, it doesn't end the matter. The "everyone/someone" argument is fine as a justification for those thinking of intervening. For those whom intervention might save, on the other hand, it is a form of cruelty: they are encouraged to think that the cavalry might come charging over the hill even if, usually, it won't. "Consistency is the hobgoblin of little minds," Ralph Waldo Emerson once said, to which the appropriate response is, "Not always, buster."
Second, it is dishonest to argue though Barack Obama has tried that humanitarian intervention has nothing to do with a desired regime change. Of course it does. If a regime is so mistreating its people that it deserves the intervention of outside forces, then it is illogical to argue that the interveners' job is done if that regime stays in power. Otherwise, why take up arms in the first place? It's sometimes argued that successful interventions such as the no-fly zone in Iraqi Kurdistan in the 1990s and the war in Kosovo did not involve regime change Saddam Hussein and Slobodan Milosevic remained as leaders of Iraq and Serbia respectively. But this entirely misses the point that change certainly did occur in Kurdistan and Kosovo, where the old regime's writ no longer ran. If the world were to decide that the human rights of Zimbabweans were so abused that armed intervention was necessary to protect them, would it be O.K. for Robert Mugabe to stay in power? Middle school kids can figure that one out.
Precisely because humanitarian intervention will often involve regime change with all the messy questions of responsibility for what comes after it many nations will shy away from getting involved. The third thing we have learned is that only some nations will ever join a robust intervention force, which limits where intervention may take place. The war in Libya is being conducted by NATO without Germany any minute now, we'll have a Glenn Miller revival with a bit of Arab participation at the margin. This is how modern interventions typically have been and will be. They are NATO shows because NATO has the muscle, the organization and three large members the U.S., France and Britain with significant constituencies supporting such intervention. But there is no equivalent to NATO anywhere else, nor any great appetite for going abroad looking for dragons to slay. Germany is not taking part in the Libyan war, and India, China, Brazil and Russia abstained from the U.N. Security Council vote that authorized it. Lots of humanity and economic clout in those five nations.
In practice, then, humanitarian intervention will take place only in parts of the world that are proximate to NATO's traditional territory Europe, the Middle East, North Africa. North Korea and Burma have for decades been run by regimes that are among the vilest on earth one starved its people in the 1990s; the other criminally failed to ameliorate the impact of a terrible cyclone in 2008 but their leaders needn't worry. Their neighbors, in Northeast Asia and Southeast Asia respectively, are immune to the instincts of the French, British and Americans to make the world a better place by force of arms.
So where does this leave us? Are there any tests that we can apply that guide when humanitarian intervention is justified? There have been many such attempts, but I am still drawn to Tony Blair's famous Chicago speech on the nation of an "international community" in 1999, at the height of the Kosovo war. Blair proposed five "major considerations" before deciding whether to intervene in the affairs of other countries. "First, are we sure of our case? War is an imperfect instrument for righting humanitarian distress; but armed force is sometimes the only means of dealing with dictators. Second, have we exhausted all diplomatic options? ... Third, on the basis of a practical assessment of the situation, are there military operations we can sensibly and prudently undertake? Fourth, are we prepared for the long term? In the past we talked too much of exit strategies. But having made a commitment we cannot simply walk away once the fight is over; better to stay with moderate numbers of troops than return for repeat performances with large numbers. And finally, do we have national interests involved?"
You can quibble with those tests, and many would the fourth of them has to be read in the knowledge that it was written before the disasters of the Iraq war. But what really strikes me about them is not just that they are sensible, but how difficult it is to satisfy them all. (How many of them were truly met in the case of Libya?) When all is said and done, justified cases of humanitarian intervention will remain rare, but the arguments over the doctrine will continue endlessly. Death and taxes, indeed.
This is an amended version of the article that ran in the April 18, 2011 international edition of TIME