President Barack Obama made this guarantee in his statement at the end of his recent Meeting of the Deputies involving the Gulf Cooperation Council national leadership seconds.

The United States is prepared to work jointly with the GCC states to deter and confront an external threat to any GCC state’s territorial integrity that is inconsistent with the UN Charter. In the event of such aggression or the threat of such aggression, the United States stands ready to work with our GCC partners to determine urgently what action may be appropriate, using the means at our collective disposal, including the potential use of military force, for the defense of our GCC partners.

Translation: we agree to talk about a response to an ongoing attack against one of you, and that response might include a military one. Hopefully, we’ll reach some sort of accommodation before you’ve been overrun.

That’s reassuring. There’s a real line there, one that should not be crossed. Else Obama might shake his finger very firmly at you.