(Slip Opinion) OCTOBER TERM, 2021 1
Syllabus
NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
being done in connection with this case, at the time the opinion is issued.
The syllabus constitutes no part of the opinion of the Court but has been
prepared by the Reporter of Decisions for the convenience of the reader.
See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.
SUPREME COURT OF THE UNITED STATES
Syllabus
CASSIRER ET AL. v. THYSSEN-BORNEMISZA
COLLECTION FOUNDATION
CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
THE NINTH CIRCUIT
No. 20–1566. Argued January 18, 2022—Decided April 21, 2022
The Foreign Sovereign Immunities Act of 1976 (FSIA), 28 U. S. C. §1602
et seq., governs whether a foreign state or instrumentality is amenable
to suit in an American court. The question in this case is what choice-
of-law rule a court should use to determine the applicable substantive
law in an FSIA suit raising non-federal claims. That issue arises in a
dispute concerning the ownership of an Impressionist painting: Ca-
mille Pissarro’s Rue Saint-Honoré in the Afternoon, Effect of Rain.
Lilly Cassirer inherited the painting, which a family member had pur-
chased from Pissarro’s agent in 1900. After the Nazis came to power
in Germany, Lilly surrendered Rue Saint-Honoré to them to obtain an
exit visa. Lilly and her grandson, Claude, eventually ended up in the
United States. The family’s post-war search for Rue Saint-Honoré was
unsuccessful. In the early 1990s, the painting was purchased by the
Thyssen-Bornemisza Collection Foundation, an entity created and
controlled by the Kingdom of Spain. Claude learned several years
later that Rue Saint-Honoré was listed in a catalogue of the Founda-
tion’s museum.
Claude sued the Foundation, asserting various property-law claims
based on the allegation that he owned Rue Saint-Honoré and was en-
titled to its return. Because the Foundation is an “instrumentality” of
the Kingdom of Spain, the complaint invoked the FSIA to establish the
court’s jurisdiction. See §1603(b). The FSIA provides foreign states
and their instrumentalities with immunity from suit unless the claim
falls within a specified exception. See §§1605–1607. The courts below
held that the Nazi confiscation of Rue Saint-Honoré brought Claude’s
suit against the Foundation within the FSIA exception for expropri-
ated property. See §1605(a)(3). That meant the Cassirer family’s suit
2 CASSIRER v. THYSSEN-BORNEMISZA COLLECTION
FOUNDATION
Syllabus
could go forward. To determine what property law governed the dis-
pute, the courts below had to apply a choice-of-law rule. The Cassirer
plaintiffs urged the use of California’s choice-of-law rule; the Founda-
tion advocated a rule based in federal common law. The courts below
picked the federal option. That option, they then held, commanded use
of the property law of Spain, not California. Applying Spanish law,
the courts determined that the Foundation was the rightful owner.
This Court granted certiorari to resolve a conflict among the Courts of
Appeals as to what choice-of-law rule a court should apply in an FSIA
case raising non-federal claims.
Held: In an FSIA suit raising non-federal claims against a foreign state
or instrumentality, a court should determine the substantive law by
using the same choice-of-law rule applicable in a similar suit against
a private party. Here, that means applying the forum State’s choice-
of-law rule, not a rule deriving from federal common law.
The FSIA provides a baseline principle of foreign sovereign immun-
ity from civil actions unless a statutory exception applies (including
the expropriation exception found to apply here). See §§1604–1607.
Yet the FSIA was never “intended to affect the substantive law deter-
mining the liability of a foreign state or instrumentality” deemed ame-
nable to suit. First Nat. City Bank v. Banco Para el Comercio Exterior
de Cuba, 462 U. S. 611, 620. To the contrary, Section 1606 of the stat-
ute provides: “As to any claim for relief with respect to which a foreign
state is not entitled to immunity under [the FSIA], the foreign state
shall be liable in the same manner and to the same extent as a private
individual under like circumstances.” When a foreign state is not im-
mune from suit, it is subject to the same rules of liability (the same
substantive law) as a private party. See First Nat. City Bank, at 622,
n. 11.
Section 1606 dictates the selection of a choice-of-law rule: It must
mirror the rule that would apply in a similar suit between private par-
ties. Only the same choice-of-law rule can guarantee use of the same
substantive law—and thus guarantee the same liability. Consider two
suits seeking recovery of a painting: one suit against a foreign-state-
controlled museum (as here), the other against a private museum. If
the choice-of-law rules in the two suits differed, so might the substan-
tive law chosen. And if the substantive law differed, so might the suits’
outcomes. Contrary to Section 1606, the two museums would not be
“liable to the same manner and to the same extent.”
In this case, Section 1606 requires the use of California’s choice-of-
law rule—because that is the rule a court would use in comparable
private litigation. Consider the just-hypothesized suit against a pri-
vate museum, brought as this case was in California and asserting
Cite as: 596 U. S. ____ (2022) 3
Syllabus
non-federal claims. If the private suit were filed in state court, Cali-
fornia’s choice-of-law rule would govern. And if the private suit were
filed in federal court, the same would be true, because a federal court
sitting in diversity borrows the forum State’s choice-of-law rule. See
Klaxon Co. v. Stentor Elec. Mfg. Co., 313 U. S. 487, 496. If California’s
choice-of-law rule applies in the private-museum suit, it must also ap-
ply in the suit here, against the Foundation. That is the only way to
ensure—as Section 1606 demands—that the Foundation, although a
Spanish instrumentality, will be liable in the same way as a private
party.
Even absent the clarity of Section 1606, the Court would likely reach
the same result. Scant justification exists for federal common lawmak-
ing in this context. Judicial creation of federal common law to displace
state-created rules must be “necessary to protect uniquely federal in-
terests.” Texas Industries, Inc. v. Radcliff Materials, Inc., 451 U. S.
630, 640. While foreign relations is an interest of that kind, here even
the Federal Government disclaims any necessity for a federal choice-
of-law rule in FSIA suits raising non-federal claims. Pp. 5–9.
824 Fed. Appx. 452, vacated and remanded.
KAGAN, J., delivered the opinion for a unanimous Court.
Cite as: 596 U. S. ____ (2022) 1
Opinion of the Court
NOTICE: This opinion is subject to formal revision before publication in the
preliminary print of the United States Reports. Readers are requested to
notify the Reporter of Decisions, Supreme Court of the United States, Wash-
ington, D. C. 20543, of any typographical or other formal errors, in order that
corrections may be made before the preliminary print goes to press.
SUPREME COURT OF THE UNITED STATES
_________________
No. 20–1566
_________________
DAVID CASSIRER, ET AL., PETITIONERS v. THYSSEN-
BORNEMISZA COLLECTION FOUNDATION
ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
APPEALS FOR THE NINTH CIRCUIT
[April 21, 2022]
JUSTICE KAGAN delivered the opinion of the Court.
Under the Foreign Sovereign Immunities Act of 1976
(FSIA), 28 U. S. C. §1602 et seq., a foreign state or instru-
mentality is amenable in specified circumstances to suit in
an American court. In this case, the plaintiffs brought such
a suit to recover expropriated property. The question pre-
sented is what choice-of-law rule the court should use to de-
termine the applicable substantive law. The answer is:
whatever choice-of-law rule the court would use if the de-
fendant were not a foreign-state actor, but instead a private
party. Here, that means applying the forum State’s choice-
of-law rule, not a rule deriving from federal common law.
I
Although the legal issue before us is prosaic, the case’s
subject matter and background are anything but. At issue
is the ownership of an Impressionist painting depicting a
Paris streetscape: Camille Pissarro’s Rue Saint-Honoré in
the Afternoon, Effect of Rain (shown in this opinion’s appen-
dix). Pissarro’s agent sold the painting in 1900 to Paul Cas-
sirer, a member of a prominent German Jewish family own-
ing an art gallery and publishing house. Some quarter
2 CASSIRER v. THYSSEN-BORNEMISZA COLLECTION
FOUNDATION
Opinion of the Court
century later, Lilly Cassirer inherited the painting and dis-
played it in her Berlin home (as also pictured in the appen-
dix). But in 1933, the Nazis came to power. After years of
intensifying persecution of German Jews, Lilly decided in
1939 that she had to do anything necessary to escape the
country. To obtain an exit visa to England, where her
grandson Claude Cassirer had already relocated, she sur-
rendered the painting to the Nazis. The underlying ques-
tion in this case—which this opinion will not resolve—is
whether the Cassirer family can get the painting back.
The post-war search for Rue Saint-Honoré was a long one.
Lilly and Claude, who both eventually ended up in the
United States, had no success tracking down the painting.
After being legally declared the rightful owner, Lilly agreed
in 1958 to accept compensation from the German Federal
Republic—about $250,000 in today’s dollars. (The painting
is now thought to be worth tens of millions.) In fact, Rue
Saint-Honoré was nearby: Like the Cassirers, the painting
had also arrived in the United States after the war, and sat
in a private collection in St. Louis from 1952 to 1976. In
that year, the Baron Hans Heinrich Thyssen-Bornemisza
(descended from the founder of a German steel empire) pur-
chased the painting and brought it back to Europe. Rue
Saint-Honoré hung at his residence in Switzerland until the
early 1990s. At that time, the Baron sold much of his art
collection, including Rue Saint-Honoré, to an entity the
Kingdom of Spain created and controlled, called the
Thyssen-Bornemisza Collection Foundation. In addition to
financing the $300 million-plus purchase, the Spanish Gov-
ernment provided the Foundation with a palace in Madrid
to serve as a museum for the collection. The museum, as
museums do, published a catalogue of its holdings. An ac-
quaintance of Claude’s saw the catalogue and made the con-
nection, telling him in 1999 where Rue Saint-Honoré was
now located. (Lilly had by then long since died, with Claude
as her sole heir.)
Cite as: 596 U. S. ____ (2022) 3
Opinion of the Court
After informal efforts to recover the painting failed,
Claude sued the Foundation in federal court in the Central
District of California, near where he then lived. His com-
plaint asserted various property-law claims, all alleging
that he owned Rue Saint-Honoré and was entitled to its re-
turn. And because the Foundation is an “instrumentality”
of the Kingdom of Spain, the complaint invoked the FSIA
to establish the court’s jurisdiction. See §1603(b) (describ-
ing an instrumentality as a legally separate but state-
controlled entity). The FSIA governs whether a foreign
state or instrumentality is amenable to suit in an American
court. It provides the sovereign actor with immunity unless
the claim against it falls within a specified exception. See
§§1605–1607. The complaint here asserted that the stat-
ute’s expropriation exception applied. That exception re-
moves immunity for cases involving “rights in property
taken in violation of international law.” §1605(a)(3). At a
prior stage of this litigation, the courts below held that the
Nazi confiscation of Rue Saint-Honoré brought Claude’s
suit against the Foundation within the expropriation excep-
tion. See 461 F. Supp. 2d 1157, 1176–1177 (CD Cal. 2006),
aff ’d, 616 F. 3d 1019, 1037 (CA9 2010) (en banc), cert. de-
nied, 564 U. S. 1037 (2011). That determination, which is
no longer at issue, meant that the suit could go forward.
(Claude, though, would not live to see anything further; he
passed away in 2010, and his heirs became the plaintiffs.)1
But go forward pursuant to what law? The courts had to
decide whose property law (Spain’s? California’s?) should
govern the suit, and thus determine the painting’s rightful
owner. Resolving that question required application of a
choice-of-law rule—a means of selecting which jurisdic-
tion’s law governs the determination of liability. Yet there
——————
1 Claude’s children, David and Ava Cassirer, along with the Jewish
Federation of San Diego County, succeeded to his claims. Some years
later, Ava also died; her estate is now a substitute plaintiff.
4 CASSIRER v. THYSSEN-BORNEMISZA COLLECTION
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Opinion of the Court
another issue lurked. For the parties contested which
choice-of-law rule should apply—serving up, so to speak, a
choice of choice-of-law principles. The Cassirer plaintiffs
urged the use of California’s choice-of-law rule; the defend-
ant Foundation advocated a rule based in federal common
law. The courts below, relying on a minimally reasoned
Ninth Circuit precedent, picked the federal option. See 153
F. Supp. 3d 1148, 1154 (CD Cal. 2015), aff ’d, 862 F. 3d 951,
961 (CA9 2017), cert. denied, 584 U. S. ___ (2018). That
federal choice-of-law rule, they further held, commanded
the use of Spanish (not Californian) property law to resolve
the ownership issue. See 153 F. Supp. 3d, at 1155, aff ’d,
862 F. 3d, at 963. Finally, the courts below determined af-
ter a trial that under Spanish law the Foundation was the
rightful owner, because it purchased Rue Saint-Honoré
without knowing the painting was stolen and had held it
long enough to gain title through possession. See No. 05–
cv–03459 (CD Cal., Apr. 30, 2019), ECF Doc. 621, pp. 26–
30, aff ’d, 824 Fed. Appx. 452, 454–455 (CA9 2020).
The Cassirers sought our review, limited to a single issue:
whether a court in an FSIA case raising non-federal claims
(relating to property, torts, contracts, and so forth) should
apply the forum State’s choice-of-law rule, or instead use a
federal one. We granted certiorari, 594 U. S. ___ (2021), be-
cause that question has generated a split in the Courts of
Appeals. The Ninth Circuit stands alone in using a federal
choice-of-law rule to pick the applicable substantive law.
All other Courts of Appeals to have addressed the issue ap-
ply the choice-of-law rule of the forum State.2 We agree
——————
2 See Barkanic v. General Admin. of Civ. Aviation of People’s Republic
of China, 923 F. 2d 957, 959–961 (CA2 1991); Northrop Grumman Ship
Systems, Inc. v. Ministry of Defense of Republic of Venezuela, 575 F. 3d
491, 498 (CA5 2009); O’Bryan v. Holy See, 556 F. 3d 361, 381, n. 8 (CA6),
cert. denied, 558 U. S. 819 (2009); Oveissi v. Islamic Republic of Iran, 573
F. 3d 835, 841 (CADC 2009).
Cite as: 596 U. S. ____ (2022) 5
Opinion of the Court
with that more common approach, and now vacate the judg-
ment below.
II
The FSIA, as indicated above, creates a uniform body of
federal law to govern the amenability of foreign states and
their instrumentalities to suit in the United States. See su-
pra, at 3. The statute first lays down a baseline principle
of foreign sovereign immunity from civil actions. See §1604.
It then lists a series of exceptions from that principle (in-
cluding the expropriation exception found to apply here).
See §§1605–1607; supra, at 3. The result is to spell out, as
a matter of federal law, the suits against foreign sovereigns
that American courts do, and do not, have power to decide.
Yet the FSIA was never “intended to affect the substan-
tive law determining the liability of a foreign state or in-
strumentality” deemed amenable to suit. First Nat. City
Bank v. Banco Para el Comercio Exterior de Cuba, 462 U. S.
611, 620 (1983). To the contrary, Section 1606 of the statute
provides:
“As to any claim for relief with respect to which a for-
eign state is not entitled to immunity under [the FSIA],
the foreign state shall be liable in the same manner and
to the same extent as a private individual under like
circumstances.”
So when a foreign state is not immune from suit, it is sub-
ject to the same rules of liability as a private party. Which
is just to say that the substantive law applying to the latter
also applies to the former. See First Nat. City Bank, 462
U. S., at 622, n. 11. As one court put the point, Section 1606
directs a “pass-through” to the substantive law that would
govern a similar suit between private individuals. Oveissi
v. Islamic Republic of Iran, 573 F. 3d 835, 841 (CADC
2009). The provision thus ensures that a foreign state, if
found ineligible for immunity, must answer for its conduct
6 CASSIRER v. THYSSEN-BORNEMISZA COLLECTION
FOUNDATION
Opinion of the Court
just as any other actor would.
And in so doing, Section 1606 also dictates the selection
of a choice-of-law rule: It, too, must mirror the rule that
would apply in a similar suit between private parties. For
only the same choice-of-law rule can guarantee use of the
same substantive law—and thus (see above) guarantee the
same liability. See Barkanic v. General Admin. of Civ. Avi-
ation of People’s Republic of China, 923 F. 2d 957, 959–960
(CA2 1991) (“[T]he same choice of law analysis” is needed
to “apply[ ] identical substantive laws,” and so to “ensure
identity of liability” between a foreign state and a private
individual). Consider two suits seeking recovery of a paint-
ing—one suit against a foreign-state-controlled museum (as
here), the other against a private museum. If the choice-of-
law rules in the two suits differed, so might the substantive
law in fact chosen. And if the substantive law differed, so
might the suits’ outcomes. In one case, say, the plaintiff
would recover the art, and in the other not. Contrary to
Section 1606, the two museums would not be “liable in the
same manner and to the same extent.”
In this case, then, Section 1606 requires the use of Cali-
fornia’s choice-of-law rule—because that is the rule a court
would use in comparable private litigation. Consider the
just-hypothesized suit against a private museum for return
of a piece of art, brought as this case was in California. The
claims asserted (again, as in this case) turn only on state or
foreign property law, with no substantive federal compo-
nent. If the private suit were filed in state court, Califor-
nia’s choice-of-law rule would of course govern. And if the
private suit were filed in federal court, under diversity-of-
citizenship jurisdiction, the same would be true. According
to long-settled precedent, a federal court sitting in diversity
borrows the forum State’s choice-of-law rule. See Klaxon
Co. v. Stentor Elec. Mfg. Co., 313 U. S. 487, 496 (1941). So
the private-museum suit would begin with the application
of California’s choice-of-law rule, to decide on the governing
Cite as: 596 U. S. ____ (2022) 7
Opinion of the Court
substantive law. And if that choice-of-law rule applies in
the private-museum suit, so too it must apply in the suit
here, against the Foundation. That is the only way to en-
sure—as Section 1606 demands—that the Foundation, alt-
hough a Spanish instrumentality, will be liable in the same
way as a private party.
In choosing instead to apply a federal choice-of-law rule,
the courts below could well have created a mismatch be-
tween the Foundation’s liability and a private defendant’s.
As described earlier, those courts found that the federal
rule commanded the use of Spanish property law to deter-
mine Rue Saint-Honoré ’s rightful owner. See supra, at 4.
Spanish law (as the courts below understood it) made eve-
rything depend on whether, at the time of acquisition, the
Foundation knew the painting was stolen: If the Founda-
tion did not know—as the courts in fact found—then it
owned the painting by virtue of possession. See ECF Doc.
No. 621, at 26–30, aff ’d, 824 Fed. Appx., at 454–455. But
now consider the possible result if the courts below had in-
stead applied California’s choice-of-law rule, as they would
have done in a private suit. The Cassirer plaintiffs contend
that the California rule would lead to the application of Cal-
ifornia property law. See Brief for Petitioners 13. And they
argue that under California property law, even a good-faith
purchaser of stolen property cannot prevail against the
rightful pre-theft owner. See ibid. We do not today decide
those questions; they remain in the hands of the lower
courts. But if the Cassirers are right, the use of a federal
choice-of-law rule in the courts below stopped Section 1606
from working: That rule led to the Foundation keeping the
painting when a private museum would have had to give it
back.
And even were Section 1606 not so clear, we would likely
reach the same result, because we see scant justification for
federal common lawmaking in this context. Judicial crea-
tion of federal common law to displace state-created rules
8 CASSIRER v. THYSSEN-BORNEMISZA COLLECTION
FOUNDATION
Opinion of the Court
must be “necessary to protect uniquely federal interests.”
Texas Industries, Inc. v. Radcliff Materials, Inc., 451 U. S.
630, 640 (1981). Foreign relations is of course an interest
of that kind. But even the Federal Government, participat-
ing here in support of the Cassirers’ position, disclaims any
necessity for a federal choice-of-law rule in FSIA suits rais-
ing non-federal claims. See Brief for United States as Ami-
cus Curiae 9, 20–23. As the Government notes, such FSIA
suits arise only when a foreign state has lost its broad im-
munity and become subject to standard-fare legal claims in-
volving property, contract, or the like. See id., at 9. No one
would think federal law displaces the substantive rule of
decision in those suits; and we see no greater warrant for
federal law to supplant the otherwise applicable choice-of-
law rule. See id., at 21 (State choice-of-law rules do not “or-
dinarily pose a greater threat to foreign relations than”
state-law principles determining “the rights and liabilities
of the parties”). Courts outside the Ninth Circuit have long
applied state choice-of-law rules in FSIA suits. See supra,
at 4, and n. 2. Yet the Government says it knows of no case
in which that practice has created foreign relations con-
cerns. See Tr. of Oral Arg. 20–21.3 So the Ninth Circuit’s
use of a federal choice-of-law rule in FSIA cases has been a
solution in search of a problem, rejecting without any rea-
son the usual role of state law.
* * *
The path of our decision has been as short as the hunt for
Rue Saint-Honoré was long; our ruling is as simple as the
——————
3 Were such an unusual case to occur, the Government states that it
would be “best addressed by applying limits on the application of state
law derived from the Constitution, applicable treaties or statutes, inter-
national comity, the Act of State doctrine, or other sources reflecting dis-
tinctly federal interests—rather than displacing state choice-of-law rules
across the board.” Brief for United States as Amicus Curiae 21; see Tr.
of Oral Arg. 20–23, 25–26. We express no view on whether or when im-
posing such limits on state law would be proper.
Cite as: 596 U. S. ____ (2022) 9
Opinion of the Court
conflict over its rightful owner has been vexed. A foreign
state or instrumentality in an FSIA suit is liable just as a
private party would be. See §1606. That means the stand-
ard choice-of-law rule must apply. In a property-law dis-
pute like this one, that standard rule is the forum State’s
(here, California’s)—not any deriving from federal common
law.
Accordingly, the judgment of the Court of Appeals for the
Ninth Circuit is vacated, and the case is remanded for fur-
ther proceedings consistent with this opinion.
It is so ordered.
APPENDIX TO OPINION OF THE COURT
Camille Pissarro, Rue Saint-Honoré in the Afternoon, Effect of Rain (1897)
Trial Exhibit #348
The painting hanging in Lilly Cassirer’s home in Germany
Trial Exhibit #10