We are again asked to bind ourselves, by treaty or by force, to the quarrels of distant powers. The question, as it has always been, is not whether we have friends among them — we have, and ought to — but whether their cause is ours.

A free nation owes its citizens a foreign policy organized around their actual interest, not around the sentiments of any season. Permanent friendships and permanent quarrels are equally unwise. The friend of yesterday may become, by circumstance, the rival of tomorrow; the rival of yesterday, the partner of necessity. Steady judgment, not standing fervor, is the proper habit of a republic.

It is fashionable in some quarters to argue that the alliances of the postwar era have outlived their usefulness, and in other quarters to argue that any reconsideration of them is betrayal. Both are mistaken in their certainty. An alliance is a tool, not a marriage. Its terms are written in language; its costs are paid in treasure; its risks are borne by the citizens who do the fighting. Each generation has the right — and the duty — to ask whether the bargain still holds.

What ought to discipline that examination is not nostalgia and not contempt, but two questions plainly put. First: does this commitment, as currently structured, serve the long-term interest of the American citizen, taking the full account of cost and the full account of benefit? Second: if not, can it be reformed without breaking the public faith on which all such instruments depend?

A republic that breaks its faith with allies casually will find its word cheap when it most needs it dear. A republic that maintains commitments out of habit alone will find its purse exhausted at the moment of true need. The middle path — the one I have always commended — is candid review, frank conversation with our partners about what we will and will not continue to do, and reform where reform is warranted, in good faith and in public.

We are not bound to the world's quarrels. We are also not free of the world. Our task is, as it always was, to walk that line with calm temper, deliberate counsel, and a clear sense of what the citizenry has actually consented to bear.