JERUSALEM, Israel - As Turkey continues its bloody incursion into northeastern Syria, some people, including former French President François Hollande have called on NATO to "suspend" Turkey's membership in the institution.
Shortly before the invasion began, US Senator Lindsey Graham (R-SC) vowed to sanction Turkey and "call for their suspension from NATO if they attack Kurdish forces who assisted the US in the destruction of the ISIS Caliphate."
But Turkey says it will not bow to the West and warned its NATO allies in Europe and the United States to get out of its way as it attacks Kurdish forces, causing the displacement of at least 130,000 people.
While some say Turkey's actions disqualify it from remaining in NATO, Dr. Aurel Sari, an Associate Professor of Public International Law at the University of Exeter, says "matters are not quite so simple."
No Provision to Suspend or Expel Member States in NATO
NATO (the North Atlantic Treaty Organization) was established in April 1949 as an international alliance primarily against the Soviet Union consisting of 12 member states from Europe and North America. The alliance has since grown to 29 member states, including Turkey which was added in 1952.
All of the members agree to uphold a political and military alliance, but unlike most international treaties, there is no official provision to expel or terminate a member state if one of them goes rogue.
"Within NATO, concerns over the behaviour of individual allies are thus resolved primarily through diplomatic means, political pressure, and by taking a long-term view," explains Sari.
Suspending a member would mean amending NATO's 70-year-old treaty, an action that requires unanimous support from all members, including Turkey.
"The historical record is that NATO deals with these problems by privately sanctioning the member violating alliance values, but does not officially terminate their membership," said Jorge Benitez, a NATO expert with the Atlantic Council think tank.
Since Turkey began the operation, fellow NATO members Norway and the US have introduced sanctions against Turkey, including blocking military exports to the country and restrictive measures against Turkey's leadership.
Even though NATO has no provision to suspend and expel misbehaving member states, Sari argues there is another option: "material breach" under Article 60 of the Vienna Convention on the Law of Treaties.
According to Article 60, material breach of a bilateral treaty by one party allows the other party to invoke the breach as "ground for terminating the treaty or suspending its operation in whole or in part."
Material Breach of a treaty consists of:
(a) A repudiation of the treaty not sanctioned by the present Convention; or
(b) The violation of a provision essential to the accomplishment of the object or purpose of the treaty
The violation of the offending party must be so severe that it "radically changes the position of every party with respect to the further performance of its obligations under the treaty."
If Turkey has indeed committed a "material breach" of the treaty, Sari says "NATO's member states would be entitled, by unanimous agreement, to suspend the operation of the treaty in whole or in part or to terminate it either in their relations with the defaulting state or among them all" without needing Turkey's approval.
Has Turkey Committed a Material Breach?
International Law professor Klauss Kress argues "there is a very serious possibility" that Turkey's invasion "could constitute a manifest violation of the prohibition of the use of force" under international law.
That, along with Turkey's threat to "open the gates" and flood Europe with millions of refugees should NATO stop him is "fundamentally at odds with the unity and solidarity of the Alliance," Sari argues.
"Characterizing these developments as a material breach is not entirely far-fetched," he says.
Ultimately, it is up to NATO to determine if Turkey's actions constitute a material breach.
"Suspending, let alone terminating, a nation's membership of NATO would be an extreme measure to be contemplated only once other attempts to restore unity and respect for the Alliance's founding principles have been exhausted," says Sari.
NATO Still Supports Turkey
NATO has taken no official steps to suspend Turkey's membership. In fact, Turkey is still in good standing with the institution.
In a joint press conference last week with Turkey's Minister of Foreign Affairs, NATO Secretary General Jens Stoltenberg said: "Turkey is a strong member of our Alliance."
"We have deep relations as NATO Allies, built over decades," he continued.
Over the years, NATO has invested more than 5 billion dollars into Turkey's military.
Referring directly to Turkey's operations in Syria, Stoltenberg said Turkey is important in the fight against terrorism and he expects "that NATO Allies will continue to provide support to Turkey, because this is something we have agreed."
He also said he expects Turkey "to act with restraint."