How the war against ISIS changed international law.

• Author: Scharf, Michael P.
• Position: Abstract through IV. The Changing Law of Self-Defense Against Non-State Actors B. Did the 9/11 Attacks Alter the Paradigm? 1. A Different Kind of Threat, p. 15-40 - New Beginnings, Resets & Pivots: The International Legal Practice of the Obama Administration

In an effort to destroy ISIS, beginning in August 2014, the United States, assisted by a handful of other Western and Arab countries, carried out thousands of bombing sorties and cruise missile attacks against ISIS targets in Iraq and Syria. Iraq had consented to the airstrikes in its territory, but Syria had not, and Russia blocked the UN Security Council from authorizing force against ISIS in Syria. The United States invoked several different legal arguments to justify its airstrikes, including the right of humanitarian intervention, the right to use force in a failed state, and the right of hot pursuit, before finally settling on self-defense. Use of force in self-defense has traditionally not been viewed as lawful against non-state actors in a third state unless they are under the effective control of that state, but the United States argued that in the aftermath of the 9/11 attacks by al Qaeda, such force can be justified where a government is unable or unwilling to suppress the threat posed by non-state actors operating within its borders. This view was not, however, initially accepted by Russia, China, or even the United Kingdom. But that changed in the aftermath of ISIS attacks against a Russian jetliner and a Paris stadium and concert hall in 2015, leading to the unanimous adoption of a UN Security Council resolution calling on States to use all necessary measures to fight ISIS in Syria without offering a legal basis for military action. This article examines the evolution of the right to use force in self-defense against non-state actors and makes the case that events in 2015 triggered a "Grotian Moment": a fundamental paradigm shift that will have broad implications for international law.

CONTENTS I. INTRODUCTION II. BACKGROUND ON THE WAR ON ISIS III. THE CONCEPT OF ACCELERATED FORMATION OF CUSTOMARY INTERNATIONAL LAW A. Nuremberg as a Grotian Moment B. Other Examples of Grotian Moments since World War II IV. THE CHANGING LAW OF SELF-DEFENSE AGAINST NON-STATE ACTORS A. Use of Force against Non-State Actors Prior to 9/11 1. State Attribution 2. Anticipatory Self-Defense under Customary International Law B. Did the 9/11 Attacks Alter the Paradigm? 1. A Different Kind of Threat 2. The International Response to 9/11 3. The Bush Doctrine C. A Grotian Moment that was Still One Case Away D. 2014: The Initial U.S. justifications for bombing ISIS 1. Humanitarian Intervention 2. Failed State 3. Hot Pursuit E. 2015: The Grotian Moment comes to Fruition V. CONCLUSION I. INTRODUCTION

In 2014, a militant group calling itself the Islamic State (ISIS) (1) rapidly took over more than thirty percent of the territory of Syria and Iraq. (2) In the process, it captured billions of dollars worth of oil fields and refineries, bank assets and antiquities, tanks and armaments, and became one of the greatest threats to peace and security in the Middle East. (3) In an effort to "degrade and defeat" ISIS, beginning in August 2014 the United States, assisted by a handful of other Western and Arab countries, launched thousands of bombing sorties and cruise missile attacks against ISIS targets in Iraq and Syria. (4) While the Iraqi government has consented to foreign military action against ISIS within Iraq, the Syrian government did not. (5) Rather, Syria protested that the air strikes in Syrian territory were an unjustifiable violation of international law. (6)

The United States initially claimed the airstrikes against ISIS were justified variously by a right of humanitarian intervention, a right to use force in the territory of failed states, and a right of hot pursuit, before settling on the argument that the airstrikes in Syria were lawful acts of collective self-defense on behalf of the government of Iraq. (7) Use of force in self-defense has traditionally not been viewed as lawful against non-state actors in a third state unless they are under the effective control of that state, (8) but the United States has argued that since the 9/11 attacks such force can be justified where a government is unable or unwilling to suppress the threat posed by the non-state actors operating within its borders. (9) This view was not, however, accepted by Russia, China, or even the United Kingdom, which initially refused to join the United States in bombing ISIS targets in Syria. (10)

Article 51 of the UN Charter provides for protection of a State's "inherent right" of self-defense. (11) Reference to an "inherent right" means the question is not one of treaty interpretation but rather discerning whether the evolving customary international law principles governing self-defense support the U.S. position. Usually, customary international law changes slowly over many decades. (12) But sometimes, world events are such that customary international law develops quite rapidly. (13) Some scholars call these transformative events and paradigm shifts (14) that accelerate the formation of customary international law "International Constitutional Moments," (15) likening them to the rapid, radical transformation in American Constitutional Law that accompanied the New Deal. (16) But because these changes occur largely outside a constitution or treaty framework, elsewhere I have made the case that a more apt term for this phenomenon is "Grotian Moment," named for Hugo Grotius, the 15th Century Dutch scholar and diplomat whose masterpiece De Jure Belli ac Pacts helped marshal in the modern system of international law. (17) This article examines whether the use of force against ISIS in Syria is one of these so-called Grotian Moments, marking a rapid change in customary international law.

The article begins with background about the nature of the ISIS threat and the U.S. decision to launch airstrikes against ISIS in Syria in August 2014. Next, it discusses the principles and process of customary international law formation and the phenomenon of accelerated formation of customary international law. Finally, it explores the evolution of the legal rationales to justify use of force against ISIS in Syria that were espoused by the United States, and the international reaction to these arguments, in order to determine whether or how the airstrikes and the international response have altered international law.

2. Background on the War on ISIS

   ISIS has its roots in the Sunni/Baathist-dominated Iraqi army of Saddam Hussein, (18) which was one of the largest armies in the world before the U.S.-led invasion of Iraq in 2003. (19) After the defeat of the Baathist regime, members of the Baathist party were banned from participating in the army or other government positions. (20) Dispossessed, marginalized, and subjugated under the U.S. occupation and subsequent Shi'ite-dominated Iraqi government of Iraqi Prime Minister Nouri al-Maliki, the former Sunni army personnel launched a protracted rebellion, with the insurgents taking on the name "al-Qaeda in Iraq" and later changing it to the "Islamic State of Iraq" (ISI). (21)

   Meanwhile, the chaos in Syria, which began as protests against the Assad regime in 2011 and escalated to full-out civil war by 2014, presented ISI an opportunity to seize territory across the border. (22) In 2014 ISI established its "capital" in the captured Syrian town of al-Raqqah and changed the group's name yet again to the "Islamic State of Iraq and Syria" (ISIS). (23) Soon thereafter, ISIS seized nearby Syrian oil wells and refineries, providing it with vast financial resources. (24)

   ISIS then turned its sights on Mosul, the second-largest city in Iraq, which fell to ISIS in 2014. (25) Following this, ISIS had access to hundreds of millions of dollars from banks, as well as tanks and armaments that it captured from the Iraqi army which fled Mosul with almost no fight. (26) With these vast financial and military resources, ISIS began to capture city after city in Iraq and Syria with ease. Meanwhile, the Maliki government's continued suppression of the Iraqi Sunnis enabled ISIS to sweep through Sunni areas in Iraq without much resistance because of resentment toward the ruling regime. (27)

   Experts believe the majority of top ISIS decision-makers are former members of Saddam Hussein's army, intelligence, and security forces. (28) But during 2014, the ranks of ISIS swelled with as many as 10,000 foreign fighters from across the Arab world and Western Europe who were attracted to its fundamentalist ideology and string of military successes. (29)

   The name Islamic State reflects the group's avowed goal to establish an Islamic caliphate across the Eastern Mediterranean. In the lands it controls, ISIS has imposed repressive edicts and conditions on the inhabitants, similar to the Taliban's former rule in Afghanistan. ISIS has beheaded thousands of Christians, Kurds and Shi'ites and destroyed Shiite shrines and archeological sites in areas under its dominion in Syria and Iraq. (30)

   ISIS's strategy of seizing and controlling territory in...