Page:Twitter v. Taamneh.pdf/3

Rh be accepted as immutable components” but should be “adapted as new cases test their usefulness in evaluating vicarious liability.” Id., at 489. Pp. 9–11.

(2) The parties then vigorously dispute what precisely a defendant must aid and abet under §2333(d)(2). Plaintiffs assert that it is “the person,” while defendants insist that it is the “act of international terrorism.” That syntactic dispute makes little difference here, because aiding and abetting is inherently a rule of secondary liability for specific wrongful acts. In the tort context, liability is imposed only when someone commits (not merely agrees to commit) an actual tort. And in this case, the ATA limits that liability to injuries caused by an “act of international terrorism,” §2333(a). It thus is not enough for a defendant to have given substantial assistance to a transcendent enterprise. A defendant must have aided and abetted (by knowingly providing substantial assistance) another person in the commission of the