Under French law pure declaratory actions, i.e. actions brought with the intention of simple consultation of the court, are usually inadmissible. The basis of this position is the fundamental procedural principle that claimants bringing proceedings before a French court need to demonstrate that they have a "legitimate interest in the success or dismissal of a claim" (article 31 of French Civil Procedure code).

The French Supreme Court has traditionally ensured application of this principle, emphasizing that judicial review must be exercised a posteriori and that a litigant cannot be guaranteed by a court, in advance, of the legality of an act, or the legitimacy of a situation.

Declaratory actions have been allowed in limited circumstances where the interest in bringing proceedings has been characterized by the need of the applicant to make clear a personal situation or assets.

Prior to the ruling of 7 December 2011 there were thus legitimate doubts as to whether proceedings could be brought before a French court seeking declaratory judgement on the jurisdiction of the court alone, and this issue had not been clearly addressed by the Supreme Court. It was even possible to infer from a previous decision of another Chamber of the Supreme Court that such a declaratory action was not admissible.

Nevertheless, in line with major French legal literature which considers that there should be no obstacle to the admissibility of such claims, the French Supreme Court decided that: "considering that they have been obliged to bring their claims before a forum that they have not chosen, the claimants have, on the grounds of the Montreal Convention, a legitimate and current interest to bring proceedings for declaratory judgement, in observation of the existence and the extent of their right of option recognised by the Montreal Convention".

The terms used by the Supreme Court in this decision seem to restrict its scope to actions based on the Montreal Convention; however, the reasoning used by the Court could well be transposed to other declaratory actions brought by claimants having a current legitimate interest in the French courts deciding on their own jurisdiction.

The Florida District Court and the Eleventh Circuit Court of Appeals acknowledged the jurisdiction of the US courts pursuant to Articles 45 and 33 of the Montreal Convention.

Regarding the application of the doctrine of forum non conveniens in the context of the Montreal Convention, the US Courts relied on Article 33(4) of the Convention which provides that "Questions of procedure shall be governed by the law of the court seized of the case" to state that "...because the doctrine of forum non conveniens is part of United States civil procedure, the Convention unambiguously permits its application in accordance with the law of the forum."

The US Courts then dismissed the case, considering France to be an available alternative, and a more adequate forum under the Montreal Convention.

The case was therefore brought by the plaintiffs before the French courts and, after several years of litigation, the French Supreme Court decided that France was "not currently available as an appropriate forum" even though it could have had jurisdiction, pursuant to article 33 of the Montreal Convention. It should be noted that the forum non conveniens doctrine is not applied under French law and the concepts of "currently available" and "appropriate forum" are unknown under French law. These were used for the first time by the French Supreme Court specifically to thwart the US FNC decisions.

The French Supreme Court considered that article 33 (1) provides the plaintiff (and the plaintiff alone) with the option to choose the forum for the lawsuit, and such a choice precludes any other court within an available forum from hearing the suit if it is not the forum selected by the plaintiff.

The French Supreme Court went further, stating that the principle that choice of the forum lies with the plaintiff may not be thwarted by reliance on any internal procedural rule.
In other words, it considers that the plaintiff's option to choose the forum for the lawsuit according to Article 33 (1) prevails over application of the procedural rules of the chosen available forum (Article 33 (4) of the Montreal Convention) .

While the purpose of the Montreal Convention (and of the Warsaw Convention) is the unification of the rules for international carriage by air, this case is a reminder that, in the absence of international jurisdiction, there is no uniformity of interpretation of the Montreal Convention.

Following the French Supreme Court's decision, the US Courts will probably have to re-examine the case.

They will probably not change their interpretation of Articles 33 (1) and 33 (4). However, they will be faced with a dilemma since they expressly stated that "forum non conveniens would permit dismissal under the Montreal Convention only if the alternative forum was authorized to hear the case under Article 33(1) or (2) and was "demonstrably the more appropriate venue." (Emphasis added)

Since the French Supreme Court ruled that under Article 33 (1) France is not available as an appropriate forum if not chosen by the plaintiff, the US Courts should therefore not be able, under the Montreal Convention, to dismiss the case on the grounds of the doctrine of forum non conveniens in favour of French Courts in future matters.

Nevertheless it seems unlikely that this decision of the Supreme Court will be extended to cover other matters as the wording is restrictive, and the decision is specifically based on the provisions of the Montreal Convention, which constitutes a rule of international jurisdiction. In cases where such a rule of international jurisdiction is absent, national courts have to apply their domestic jurisdiction rules, none of them prevailing over others.