Document ID: ./input/supremecourt_opinions/opinions/17pdf/16-499_1a7d.pdf
Page Number: 60

Cite as:  584 U. S. ____ (2018) 

3 

SOTOMAYOR, J., dissenting 

gorical  question  whether  corporations  may  be  sued  under 
the  ATS  as  a  general  matter.    International  law  imposes
certain obligations that are intended to govern the behav­
ior  of  states  and  private  actors.  See  id.,  at  714–715;  1 
Restatement  (Third)  of  Foreign  Relations  Law  of  the
United  States,  pt.  II,  Introductory  Note,  pp.  70–71  (1987) 
(Restatement).  Among  those  obligations  are  substantive 
prohibitions  on  certain  conduct  thought  to  violate  human
rights, such as genocide, slavery, extrajudicial killing, and 
torture.  See  2  Restatement  §702.    Substantive  prohibi­
tions  like  these  are  the  norms  at  which  Sosa’s  step-one 
inquiry is aimed and for which Sosa requires that there be
sufficient international consensus. 

Sosa does not, however, demand that there be sufficient 
international consensus with regard to the mechanisms of 
enforcing  these  norms,  for  enforcement  is  not  a  question
with  which  customary  international  law  is  concerned. 
Although  international  law  determines  what  substantive
conduct  violates  the  law  of  nations,  it  leaves  the  specific
rules of how to enforce international-law norms and remedy 
their violation to states, which may act to impose liability 
collectively  through  treaties  or  independently  via  their 
domestic  legal  systems.  See,  e.g.,  L.  Henkin,  Foreign
Affairs  and  the  United  States  Constitution  245  (2d  ed.
1996)  (“International  law  itself  . . .  does  not  require
any  particular  reaction  to  violations  of  law”);  Denza,
The  Relationship  Between  International  and  National
Law,  in  International  Law  423  (M.  Evans  ed.  2006) 
(“[I]nternational law does not itself prescribe how it should 
be  applied  or  enforced  at  the  national  level”);  1  Restate­
ment  §111,  Comment  h  (“In  the  absence  of  special  agree­
ment, it is ordinarily for the United States to decide how it 
will  carry  out  its  international  obligations”);  Brief  for 
International Law Scholars as Amici Curiae 9–10. 

In  keeping  with  the  nature  of  international  law,  Sosa 
consistently  used  the  word  “norm”  to  refer  to  substantive