In Praise of Neagle

• Pages: 155-188
• Date: 01 July 2025
• Published date: 01 July 2025
• Author: William R. Casto

ARTICLES

In Praise of Neagle

William R. Casto*

I. INTRODUCTION

In re Neagle

1

is an obscure (albeit colorful) nineteenth century case that

decided a no-brainer legal issue.

2

The Supreme Court held that if a Supreme-

Court justice’s life is threatened, the Executive may provide the justice with a

bodyguard. Neagle should have lapsed into obscurity

3

, but in the last sixty years,

it has become a go-to precedent for an expansive unilateral presidential power to

launch military attacks on foreign nations.

4

This essay explores Neagle’s rele-

vance to the law of foreign affairs and the Constitution.

Neagle actually involved a case within a case. The Court’s ho-hum decision

that the president has power to protect the lives of Supreme Court justices has no

signif‌icance today. To repeat, it is a no brainer. The important aspect of the case

is the Court’s reliance upon a then well-known foreign affairs incident to support

the existence of implied constitutional powers. In 1853, an American sloop-of-

war threatened to attack an Austrian naval vessel in order to rescue Louis Koszta,

* Paul Whitf‌ield Horn Distinguished Professor, Texas Tech University School of Law. Professor

Casto is a legal historian who has written many books and articles on national security. I thank Bryan

Camp, Geoffrey Corn, Scott Gerber, John Gordon III, and Peter Raven-Hansen for their helpful

comments and suggestions. © 2025, William R. Casto.

1. Cunningham v. Neagle, 135 U.S. 1 (1890). The case actually has two names. It was denominated

In re Neagle in the trial court. 39 F. 833 (N.D. Cal. 1889). In the Supreme Court, it was styled

Cunningham v. Neagle. 135 U.S. To add to the confusion, the running head of Cunningham in the U.S.

Reports is In re Neagle. Today most people call it In re Neagle. There are three good treatments of the

Neagle case. See CARL SWISHER, The Terry Tragedy, in STEPHEN J. FIELD, CRAFTSMAN OF THE LAW

321, 321-61 (1930); PAUL KENS, JUSTICE STEPHEN FIELD: SHAPING LIBERTY FROM THE GOLD RUSH TO

THE GILDED AGE 276-83 (1997); John Harrison, The Story of In re Neagle: Sex, Money, Politics,

Perjury, Homicide, Federalism, and Executive Power, in PRESIDENTIAL POWER STORIES 133

(Christopher Schroeder & Curtis A. Bradley eds., 2009). Swisher’s book is the best for the case’s

colorful background.

2. In Neagle, “the Court spent considerable energy demonstrating what no one would now deny. . .”

Henry Monaghan, The Protective Power of the Presidency, 93 COLUM L. REV. 1, 61 (1993).

3. The case bemused Professor John Harrison: “W]hat is this soap opera doing in the United States

Reports?” Harrison, supra note 1, at 133. Rather than emphasize the Court’s treatment of implied

presidential authority, Harrison analyzed the case in terms of federalism and the growth of the national

government’s authority to interfere with states. Harrison, supra note 1, at 133. Owen Fiss’s Holmes-

Devise treatment relegated Neagle to two sentences with no analysis of the issues. 8 OWEN M. FISS, THE

OLIVER WENDELL HOLMES DEVISE HISTORY OF THE SUPREME COURT OF THE UNITED STATES:

TROUBLED BEGINNINGS OF THE MODERN STATE, 1888-191029-30 (1993).

4. See infra notes 10-18 and accompanying text.

155

an American citizen,

5

held prisoner in the Austrian ship.

6

The Neagle Court

clearly stated that this incident was an example of the Executive’s implicit unilat-

eral constitutional authority to risk war in rescuing Americans held captive

overseas.

7

As a matter of taxonomy, we must distinguish between a state’s right under

international law and a state’s internal allocation of powers. There is little doubt

that under international law a state may, in some circumstances, properly use

force to protect its nationals overseas,

8

but Neagle’s discussion of the Koszta

Affair did not involve international law. Rather, Neagle/Koszta addressed the in-

ternal law issue of whether the Executive has unilateral power to protect our citi-

zens abroad. The Koszta Affair involved the Constitution’s allocation of powers

between the president and the Congress.

The Neagle/Koszta Principle has never been mentioned in any judicial opinion

dealing with the president’s foreign-affairs powers.

9

In contrast, the Executive

Branch has been touting the importance of Neagle/Koszta for over a century.

10

Legal advisers used the principle to justify the rescue of the crew of the spy-ship

Mayaguez.

11

When President Jimmy Carter launched an unsuccessful surprise

attack on Iran, Neagle/Koszta was there. Carter’s White House Counsel advised

“The President’s [C]onstitutional power to use the armed forces to rescue

5. Actually, Koszta was a Hungarian who had applied for U.S. citizenship. The Secretary of State

later defended the rescue on the basis that Koszta had applied for citizenship and was domiciled in the

United States. See infra note 113 and accompanying text.

6. Neagle, 135 U.S. at 64-65.

7. Id. Accord id. at 84-85 (Lamar, J., dissenting).

8. See THOMAS M. FRANCK, RECOURSE TO FORCE: STATE ACTION AGAINST THREATS AND ARMED

ATTACKS (2002); see also EDWIN M. BORCHARD, THE DIPLOMATIC PROTECTION OF CITIZENS ABROAD

OR THE LAW OF INTERNATIONAL CLAIMS 570-72 (1915) (discussing “Koszta’s Case”).

9. In the Youngstown Sheet & Tube Co. v. Sawyer, Chief Justice Vinson dissented and used Neagle

for the general proposition that the president has implied constitutional powers. 343 U.S. 579, 687

(1952). The Chief Justice made no mention of the Koszta Affair. Nor did he portray Neagle as related to

the president’s foreign-affairs powers.

In Haitian Refugee Center, Inc. v. Gracey, the court used Neagle to support the president’s

interdiction of illegal immigration on the high seas. 600 F. Supp. 1396, 1400 (D.D.C. 1985). The court

did not mention the Koszta Affair. In a lengthy decision aff‌irming the trial court’s decision, the appellate

court made no mention of Neagle. Haitian Refugee Center, 809 F. 2d 791 (D.C. Cir. 1987).

10. In 1912, the solicitor of the Department of State relied upon Neagle’s treatment of Koszta to

establish implied authority to use military force to protect our citizens overseas. U.S. Dep’t of State,

Right to Protect Citizens in Foreign Lands, Memorandum of the Solicitor for the Department of State,

October 5, 1912 45-56 (3rd ed. 1933).

11. Regarding the Mayaguez rescue, Roderick Hills, Counsel to the President, explained that “[w]e

should not assume that Congress would lightly interfere with the true constitutional war powers of the

president—and what could be more at the heart of the true power than assuring . . . the safety American

citizens?” Anthony Lewis, He Was Concerned about the Legal Prohibition on All Indochina Combat,

NEW YORK TIMES (May 18, 1975) (quoting Hills). Accord, War Powers: A Test of Compliance Relative

to the Danang Sealift, the Evacuation at Phnom Penh, the Evacuation of Saigon, and the Maraguez

Incident: Hearings before the Subcomm. on Int’l Sec. & Scientif‌ic Affairs of the H. Comm. on Int’l

Relations, 94th Cong. 29-31 (1975) (memorandum supplied by the Dep’ts of State and Defense

regarding the President’s authority to use the armed forces to evacuate U.S. citizens and foreign

nationals from areas of hostility”) [hereinafter War Powers]. See also Monaghan, supra note 2, at 71.

156 JOURNAL OF NATIONAL SECURITY LAW & POLICY [Vol. 15:155

Americans illegally detained abroad is clearly established [by] In re Neagle.”

12

In

the aftermath of 9/11, Professor John Yoo was in the Off‌ice of Legal Counsel

(OLC). He loved Neagle and cited it for an expansive presidential “power to

[provide]. . . ‘all the protection implied by the nature of the government under the

Constitution.”

13

He obviously read Neagle as establishing presidential power to

rescue Americans abroad.

Neagle’s embrace of the Koszta Affair can also be glimpsed behind the cur-

tains in a number of other attacks on foreign nations. When President Ronald

Reagan bombed Libya, his State Department legal adviser testif‌ied, “The

President has constitutional power as Commander-in-Chief and as the nation’s

principal authority for the conduct of foreign affairs, to direct and deploy U.S.

forces in the exercise of self-defense, including the protection of American citi-

zens from attacks abroad.”

14

Likewise, when President Bush invaded Panama,

he explained that it was done in part “to protect American lives. . .”

15

Neagle/

Koszta popped up again when we invaded Grenada.

16

In 1989, Neagle appeared

to limit the extraterritorial reach of the Posse Comitatus Act.

17

A few decades

later in 2014, Neagle/Koszta made another appearance, this time to support tar-

geted airstrikes in the Middle East.

18

In addition to Neagle, the Executive Branch has relied upon another ancient

relic, Durand v. Hollins,

19

to support a broad array of unilateral military opera-

tions overseas. Durand is a quite obscure 1860 trial-court decision. Sometimes

12. The Situation in Iran, Hearing Before the S. Comm. on Foreign Relations, 96th Cong., at 48

(1980) (legal opinion by Lloyd Cutler). See infra notes 198-202 and accompanying text.

13. The President’s Constitutional Authority to Conduct Military Operations Against Terrorists and

Nations Supporting Them, 25 Op. O.L.C. 188, 188 (2001). Whether Neagle provides a proper basis for

this broad ranging power is questionable. LOUIS HENKIN, FOREIGN AFFAIRS AND THE UNITED STATES

CONSTITUTION 348 n.54 (2d ed. 1996).

14. War Powers, Libya and State-Sponsored Terrorism: Hearings before the Subcomm. on Arms

Control, International Security and Science of the Comm. on Foreign Affairs, 99

th

Cong. 18 (1986)

(emphasis added).

15. Letter from George Bush, President of the U.S., to the Speaker of the House of Representatives

and the President Pro Tempore of the Senate, on United States Military Action (Dec. 12, 1989).

16. Professor Henry Monaghan inferred that the legality of the invasion of Grenada was based upon

Neagle. Monaghan, supra note 2, at 71. In the popular imagination, the purpose of the Grenada invasion

was to protect U.S. medical students endangered on the island. See, e.g., HEARTBREAK RIDGE (Warner

Bros., Inc. 1986). In a national television address, President Ronald Reagan announced our invasion of

Grenada “to protect innocent lives, including up to a thousand Americans, whose personal safety is,

of course, my paramount concern.” Remarks of the President and Prime Minister Eugenia Chales of

Domenica Announcing the Deployment of United States Forces to Grenada, 2 PUB. PAPERS 1506 (Oct.

25, 1983). Similarly, Deputy Secretary of State Kenneth Dam insisted that the invasion was mounted “to

secure and evacuate endangered U.S. citizens.” U.S. Dep’t of State, Bureau of Pub. Affairs, The Larger

Importance of Grenada 4 (Nov. 4, 1983).

17. Extraterritorial Effect of the Posse Comitatus Act, 13 Op. O.L.C. 321, 331-32 n.9 (1989). For

another 1989 use of Neagle, see Authority of the Federal Bureau of Investigation to Override

International Law in Extraterritorial Law Enforcement Activities, 13 Op. O.L.C. 163, 176-77 (1989)

[hereinafter Authority to Override].

18. Targeted Airstrikes Against the Islamic State of Iraq and the Levant, 38 Op. O.L.C. 82, 99 (2014).

19. 8 F. Cas. 111 (S.D. N.Y. 1860). See infra notes 137-80 and accompanying text.

2025] IN PRAISE OF NEAGLE 157