Laudator Temporis Acti

Horace, Epistles 1.2.14 (tr. H. Rushton Fairclough):

Whatever folly the kings commit, the Achaeans pay the penalty.

quidquid delirant reges, plectuntur Achivi.

Roland Mayer ad loc.:

14 A summary, perhaps relying on a proverb found as early as Hesiod (Otto §1536), cf. Phaedr. 1.30.1 humiles laborant ubi potentes dissident. quidquid is internal acc. with delirant (G-L §333, Roby §1094). plectuntur, often of undeserved punishment (Palmer on Ov. Ep. 11.110), refers both to the plague sent by Apollo in Il. 1 to pay back the Achaeans for the theft of Chryseis as well as to the unnecessarily protracted fighting.

Mayer here seems at least partially dependent on Augustus S. Wilkins ad loc.:

quicquid, Roby § 1094, S. G. § 461. plectuntur, Sat. II. 7, 105 tergo plector 'I pay for it with my back'. The word is often used of undeserved or vicarious punishment: cp. Ov. Her. xi. 110 a! miser admisso plectitur ille meo! (with Palmer's note).

Quintus Horatius Flaccus, Briefe. Erklärt von Adolf Kiessling. 4. Auflage bearbeitet von Richard Heinze (Berlin: Weidmann, 1914), p. 26:

v. 14 gibt in antithetisch pointierter und allgemein gefaßter Sentenz den zweiten Vers des Iliasprooemiums wieder: (μῆνιν) οὐλομένην, ἣ μυρί᾽ Ἀχαιοῖς ἄλγε᾽ ἔθηκε, und hebt somit den Einzelfall zur Geltung einer ewigen Wahrheit empor; der Gedanke an das Leid, das der Zwist der römischen principes über das ganze Volk gebracht hat, wird H. nicht fern gelegen haben.

As Kiessling and Heinze indicate, this line from Horace expresses a nearly universal truth.