From the National Interest: But the fact of the matter is that NATO went to war in Afghanistan, invoking Article V’s declaration that an “attack against one” shall be “considered an attack against them all” in the aftermath of the 9/11 attacks. The Taliban government that sheltered al-Qaeda has been ousted and hundreds of the terrorist group’s leaders have been killed. The original mission has long since morphed into an incredibly ambitious nation-building exercise with murky goals.

NATO would never have achieved consensus on undertaking such a mission, even in the emotional wake of 9/11. Why, then, should its future rest on its achievement? . . .

If nation-states manage to slog on after losing or giving up on wars, why should alliances be any different?