As I wrote last week, Michael W. Doyle has just put out a terrific book, The Question of Intervention: John Stuart Mill & the Responsibility to Protect. We hosted a discussion of the book at Cato on Thursday, and the event will eventually air on C-Span’s BookTV.

I read and re-read Mill’s classic essay, “A Few Words on Non-Intervention” in preparation for the event (excerpts are available here; full text here), and I was struck by how relevant it is the present day.

Mill starts his essay with a reference to “a country in Europe,” spelling out its characteristics before naming it.

“No country apprehends. . . from it any aggressive designs.”

“Any attempt it makes to exert influence over [other nations], even by persuasion, is rather in the service of others, than of itself.”

“Not only does this nation desire no benefit to itself at the expense of others, it desires none in which all others do not as freely participate.”

“Whatever it demands of itself it demands for all mankind.”

Mill was speaking, of course, of England in the mid-nineteenth century. But this is also how foreign policy makers and elites talk about U.S. foreign policy in the early twenty-first century. These same principles, so the conventional wisdom says, also explain the occasions for when, and whether, the United States resorts to the use of force, or the threat to use force.

No legitimate critique of U.S. foreign policy can ever ascribe to us aggressive designs. We act always in the service of others. And we hold ourselves to the same standards that we hold everyone else. The U.S. role in the world is not merely to advance the safety and security of Americans, but also the interests and well-being of all mankind. Indeed, to proclaim that self-interest should guide the conduct of U.S. foreign policy would be tantamount to rejecting what most U.S. foreign policy elites define as American Exceptionalism.

But, of course, the United States does not always intervene on behalf of others. And the criteria explaining why we do, when we do, are unclear. Responsible policymakers, or those who aspire to be, should undertake a reasonable effort to describe a set of conditions, or even items for consideration, before we intervene militarily abroad. (I’ve done so here; see also Ian Bremmer’s work along these lines).

Doyle’s book, and Mill’s original essay, could help. Mill strongly advised against aligning with governments who were actively suppressing their people, what my colleagues Ted Galen Carpenter and Malou Innocent call our “perilous partners.” “A government which needs foreign support to enforce obedience from its own citizens,” Mill wrote, “is one which ought not exist; and the assistance given to it by foreigners is hardly ever anything but the sympathy of one despotism over another.”

He was similarly skeptical of intervening to help overthrow an indigenous government—a government comprised entirely of the people of that same country, and not a foreign occupier. By this standard, Mill would have opposed the war in Iraq in 2003.

Michael Doyle, echoing Mill, reminds us that “not every oppressive abuse that justifies a rebellion by locals justifies an intervention by foreigners. Humanitarian duties are contextual, and self-determination constrains humanitarian concerns.” Put another way, no one should expect the United States, or any other country, to gravely endanger its own national security in the service of humanitarian principles.

We cannot confine ourselves merely to questions of whether it is permissible under international law, to intervene by force in the internal affairs of a foreign state. We must also assess the likelihood of success beforehand, and we must revisit the interventions after the fact. Did they actually advance the cause of universal human rights? Did a given intervention bestow upon some number of people the ability to govern themselves? And, if it afforded them that chance, but they ultimately failed to do so, is that the fault of us, as interveners, or of those on whose behalf we intervened?

Most such interventions fail, with the countries lapsing back into “civil war, a deepened autocracy, or imperial rule.” Meanwhile, the successful ones have often entailed considerable costs and risks on the part of the intervener, particularly if the intervention included a lengthy post-conflict occupation, which, under modern norms, it must. (Recall Colin Powell’s Pottery Barn rule.)

The unhappy experience in Libya 2011 informed the Obama administration’s refusal to intervene decisively in Syria in 2012. And when they seemed poised to do so in the late summer of 2013, the American people rose up in opposition. Had Obama sought congressional authorization, he would have lost. The American people preferred to stay out.

That is as it should be. The burden of proof should always be on those making the case for intervention. Mill’s wise counsel still holds.

Christopher A. Preble is vice president for defense and foreign policy studies at the Cato Institute.

Image: Flickr/U.S. Department of Defense.