The U.S. troops are in Syria, and their number has just been increased. Under what international law is the deployment of U.S. troops in Syria justified?

  • 2
    The U.S. law in question is the post-9-11 AUMF. Not sure that it has to be justified under international law. There is an anti-ISIS UN Resolution, although I'm not sure that it specifically covers deployment of foreign ground troops. un.org/press/en/2015/sc12168.doc.htm More UN resolutions related to Syria are at securitycouncilreport.org/un-documents/syria – ohwilleke Mar 12 '17 at 0:05
  • Justified by whom? Do you mean what argument does the US make to claim that its deployment of US forces in Syria is supported by International law? If so, do you have some reason to think the US is making any such argument? Traditionally, the US's position (as pretty much all other countries) is that it will deploy its troops as it sees fit to preserve its national security and it doesn't matter what people claim international law is or says. – David Schwartz Mar 12 '17 at 0:31
  • 1
    @DavidSchwartz - No, I don't see the US making such an argument in the case of Syria. However, in the past (Yugoslavia, Libya, and Iraq come to mind), the US tried to secure some level of international/UN support before using military power abroad. Why not in Syria? – ebhh2001 Mar 12 '17 at 4:29
  • @ebhh2001 So is the question whether or not the US has actually tried to justify the troops in Syria under international law? Whether they could be justified by international law? Or something else? – David Schwartz Mar 12 '17 at 4:46
  • @DavidSchwartz - the question is indeed whether the current US troops deployment to Syria can be justified by international law. – ebhh2001 Mar 13 '17 at 2:16

Under contemporary international law, a military action could only be justified in three ways:

  • an act of self defense is justified;
  • collective self-defense, or a military action to aid an attacked ally, pursuant to a treaty of mutual defense, is justified;
  • an international organization with peacekeeping functions, e.g. the United Nations (through its Security Council) or the African Union, may order military intervention.

A fourth justification for military action, counter-terrorism, is being incorporated into international law gradually. Other than these, all military actions are not justified.

The U.S. claims that its justification for military deployment in Syria is counter-terrorism against Daesh. However, this justification isn't absolutely accepted by normative international law yet. Thus, it's hard to say if American military actions in Syria are justified.

However, the international community is anarchic in nature, and there is really no one to enforce international law. There's no international police who could go into the White House and arrest the President and his cabinet members because they have violated international law. The only way to counteract against an act of invasion is either to repel the attack legitimately (which Assad is incapable of), to invoke mutual defense pacts (which Syria is not in), or to wait for the UN to direct military intervention (which is impossible, because the US has a veto in the Security Council).

Most of the contemporary US military actions abroad are unjustified or barely justified by international law, but no one can do anything about it anyway. International law is followed by most states at most occasions, but everyone do so on a good faith basis - just like how we generally follow accepted rules of ethics and conduct. No one can force you to, but doing so is generally to the interest of everyone.


The US Troop deployment in Syria has not been issued under international law. It is backed by the Authorization for Use of Military Force Against Terrorists (aka AUMF). This is a post-911 document that was originally issued for president Bush to fight against Al-Qaeda. It has since been used (controversially) as a justification for many military actions due to the vagueness and broadness of the scope defined.

...the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons.

This is one of the foundational documents of what is frequently known as the "war on terror". In late 2016 the Obama administration published an interpretation of the AUMF that justified military action against ISIS. The current military action is support for an offensive against ISIS, so it would fall under that scope.

  • 2
    Summary: it's not justified by International Law. – Sjoerd Apr 10 '17 at 16:46
  • @Sjoerd Did you read my very first sentence? – David says Reinstate Monica Apr 10 '17 at 16:54
  • 2
    Yes. The rest of the text does not answer the question - which is about International Law - so I summarized it. – Sjoerd Apr 10 '17 at 16:58
  • @Sjoerd The first first sentence explains all the relevant info about international law. The rest of the answer explains whats actually going on. Your summary is incomplete. – David says Reinstate Monica Apr 10 '17 at 17:14

Self created resolutions and legal justifications are by no means valid in an international court of law. However, historically the US has violated international law by transgressing the sovereign borders of foreign countries in pursuit of military intervention and regime change. They have done this without the consent of the United Nations Security Council or the approval of sovereign countries where they have placed their troops. This is known as American Exceptionalism...a self-centered view that it has the right to do what it wants when it wants simply because it is powerful enough to do so. It is also known as Empire's Law.

  • 2
    Any references to support the claims? – Alexei Jan 29 '18 at 13:46

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .