ISIS has changed international law

Two years ago, virtually no one had heard of the Islamic State of Iraq and Syria (ISIS). In a January 2014 New Yorker interview, President Obama dismissed the group as “Junior Varsity.” Since then, ISIS has emerged as one of the most wealthy, powerful, and dangerous terrorist organizations that ever existed.

ISIS now possesses more than $2 billion in stolen cash, thousands of captured tanks and bombs, as well as lucrative oil wells and refineries in the large parts of Syria and Iraq that it has taken over.

In these areas, the United States has determined, ISIS is committing genocide against Christians, Shi’a Muslims, and Yazidis. Beheadings, burning people alive, mass rape – these are the methods of ISIS terror.

But the ISIS threat is not confined to the Middle East.

In October they bombed a Russian airliner, in November they attacked Paris and, most recently, on 22 March, ISIS terrorists bombed the Brussels airport and a key train station. These attacks have left 650 Westerners dead and over a thousand injured. Any city in the world could be the target of the next ISIS attack.

As former counsel to the Counter Terrorism Bureau and attorney adviser for United Nations affairs at the U.S. Department of State, I have been lecturing and writing about the international rules governing use of force for decades.

In my 2013 book, Customary International Law in Times of Fundamental Change, I speculated that events unfolding in Syria might bring about a radical change in international law.

It turns out that they have.

In newly published research, I reveal how the urgent need to respond with force to ISIS has redefined the use of “self-defense” in international law to include attacking a nonstate threat in another country.

The scenario
Since August 2014, the United States has carried out 20,000 bombing and cruise missile attacks against ISIS targets in Iraq and Syria.

Iraq consented to the air strikes in its territory, but Syria didn’t. And Russia blocked the United Nations Security Council from authorizing force against ISIS in Syria.

For two years, the United States was virtually alone in its efforts. Russia, China and even the United States’ staunchest ally, the United Kingdom, felt that the United States could not justify its bombings under existing international law.