Document ID: ./input/supremecourt_opinions/opinions/13pdf/12-158_6579.pdf
Page Number: 56

Cite as:  572 U. S. ____ (2014) 

15 

THOMAS, J., concurring in judgment 

At  least  until  recently,  the  original  understanding  that 
the Treaty Power is limited was widely shared outside the 
Court as well.  See Golove 1288 (“[V]irtually every author-
ity,  including  the  Supreme  Court,  has  on  countless  occa-
sions  from  the  earliest  days  recognized  general  subject 
matter limitations on treaties”).  The Second Restatement 
on  the  Foreign  Relations  Law  of  the  United  States,  for 
example, opined that the Treaty Power is available only if
the  subject  matter  of  the  treaty  “is  of  international  con-
cern.”  §117(1)(a)  (1964–1965).  The  Second  Restatement 
explained  that  a  treaty  “must  relate  to  the  external  con-
cerns  of  the  nation  as  distinguished  from  matters  of  a 
purely internal nature.”  Id., Comment b; see also Treaties 
and Executive Agreements: Hearings on S. J. Res. 1 before 
a  Subcommittee  of  the  Senate  Committee  on  the  Judici-
ary,  84th  Cong.,  1st  Sess.,  183  (1955)  (Secretary  of  State 
Dulles)  (Treaties  cannot  regulate  matters  “which  do  not
essentially  affect  the  actions  of  nations  in  relation  to
international  affairs,  but  are  purely  internal”);  Proceed-
ings of the American Society of International Law 194–196 
(1929)  (C.  Hughes)  (“[The  Treaty  Power]  is  not  a  power 
intended  to  be  exercised  . . .  with  respect  to  matters  that 
have  no  relation  to  international  concerns”).    But  see 
Restatement  (Third)  of  Foreign  Relations  Law  of  the
United  States  §302,  Comment  c  (“Contrary  to  what  was
once suggested, the Constitution does not require that an
international  agreement  deal  only  with  ‘matters  of  inter-
national  concern’ ”).  At  a  minimum,  the  Second  Restate-
ment  firmly  reflects  the  understanding  shared  by  the 
Framers  that  the  Treaty  Power  has  substantive  limits. 
Only  in  the  latter  part  of  the  past  century  have  treaties 

—————— 

regulations for the protection of birds which regularly migrate between 
the  United  States  and  Canada”—the  Solicitor  General  concluded  that 
the treaty concerned “a proper subject of negotiations.”  Ibid.