When the war of words predicts the war of arms: Discursive alignment and joint military intervention in six civil wars

When do public diplomatic speeches at the United Nations Security Council predict joint military intervention in civil wars, and when do they not? This note argues that states coordinate joint intervention through two substitutable mechanisms: public costly signaling in multilateral forums and private bilateral bandwidth. Which mechanism prevails depends on the visibility of the conflict theater. Where extra-regional major powers fight directly, intervention cannot be hidden, and prospective partners must first converge on a shared public framing; their rhetorical alignment at the Council therefore foreshadows their joint action. Where the kinetic core is regional and covert, public alignment is a liability, and coordination retreats into the private channels of alliances and bilateral ties. The argument is tested with the Discursive and Kinetic Intervention Corpus (DKIC), a new dyadic dataset linking Security Council speech records to UCDP external-support data across six civil wars: the Second Congo War, Sudan/Darfur, Somalia, Syria, Libya, and Yemen. The similarity of two states’ conflict rhetoric predicts their subsequent joint intervention in proportion to the share of the conflict’s fighting carried out by the Council’s permanent members. The relationship withstands alternative text measures, rare-events corrections, and the exclusion of any single conflict, though Syria supplies most of the case-level evidence and is the only conflict where the effect is individually significant. Structural ties remain strong predictors of intervention everywhere. Public words anticipate joint arms where war is waged in the open; where it is waged covertly, the quiet leverage of structural ties does the coordinating.