Peace proposals unaccompanied by a sworn covenant indicate a plot.
Tu Yu defines 約 as 要約, and Li Ch‘üan as 質盟之約 “a treaty
confirmed by oaths and hostages.” Wang Hsi and Chang Yü, on the
other hand, simply say 無故 “without reason,” “on a frivolous
pretext,” as though 約 bore the rather unusual sense of
“important.” Capt. Calthrop has “without consultation,” which is
too loose.