Citation: 4A_65/2018 E. B

B.a. Le 10 juillet 1995, l'Allemagne et l'Inde ont signé un accord sur l'encouragement et la protection réciproques des investissements (ci-après: le TBI, pour traité bilatéral d'investissement). En tant qu'il intéresse la présente procédure de recours, ledit accord, entré en vigueur le 13 juillet 1998, contient notamment les dispositions suivantes: " The Federal Republic of Germany and the Republic of India (hereinafter referred to as the Contracting Parties) Desirous of creating conditions favourable for fostering greater investment by nationals and companies of either State in the territory of the other State Recognising that reciprocal protection of such investments under an agreement will subserve the aforesaid objective and will be conducive to the stimulation of individual business initiative and will increase prosperity in both States Have agreed as follows" " Article 1 Definitions For the purpose of this Agreement: (a) "Companies" means: (i) in respect of the Republic of India: corporations, firms and associations incorporated or constituted under the law in force in any part of India; (ii) in respect of the Federal Republic of Germany juridical persons as well as commercial or other companies or associations with or without legal personality having their seat in the territory of the Federal Republic of Germany, irrespective of whether or not their activities are directed at profit; (b) "Investment" means every kind of asset invested in accordance with the national laws of the Contracting Party where the investment is made and, in particular, though not exclusively, includes: (i) movable and immovable property as well as other rights such as mortgages, liens, or pledges; (ii) shares in, and stock and debentures of, a company, and any other forms of such interests in a company; (iii) right to money or to any performance under contract having a financial value; (iv) intellectual property rights, including patents, copyrights, registred designs, trade marks, trade names, technical processes, know-how and goodwill in accordance with the relevant laws of the respective Contracting Party; (v) business concessions conferred by law or under contract, including concessions for mining and oil exploration; (c) "Investor" means nationals or companies of a Contracting Party who have effected or are effecting investment in the territory of the other Contracting Party; -." " Article 2 Scope of the Agreement This Agreement shall apply to all investments made by investors of either Contracting Party in the territory of the other Contracting Party, whether made before or after the coming in force of this Agreement." "Article 3 Promotion and Protection of Investment (1) Each Contracting Party shall encourage and create favourable conditions for investors of the other Contracting Party and also admit investments in its territory in accordance with its law and policy. (2) Each Contracting Party shall accord to investments as well as to investors in respect of such investments at all times fair and equitable treatment and full protection and security in its territory. (3) Neither Contracting Party shall place any constraints on the international movement of goods or persons directly connected with an investment being transported subject to bilateral or international agreements governing such transports, which are in force between the Contracting Parties." " Article 5 Expropriation or Nationalisation (1) Investments of investors of either Contracting Party shall not be expropriated, nationalised or subjected to measures having effect equivalent to nationalisation or expropriation in the territory of the other Contracting Party except in public interest, authorised by the laws of that Party, on a non-discriminatory basis and against compensation which shall be equivalent to the value of the expropriated or nationalised investment immediately before the date on which such expropriation or nationalisation became publicly known. Such compensation shall be effectively realisable without undue delay and shall be freely convertible and transferable. Interest shall be paid in a fair and equitable manner for the period between the date of expropriation or nationalisation and the date of actual payment of compensation. (2) An investor whose investment is expropriated or nationalised may, under laws of the Contracting Party making the expropriation or nationalisation, seek review of expropriation or nationalisation measures by a judicial or other independent authority of that Contracting Party. (3) Where a Contracting Party expropriates the assets of a company in its own territory, in which investors of the other Contracting Party own shares, it shall ensure that the provisions of paragraphs 1 and 2 of this Article are applied in the same manner to provide compensation in respect of the investment of such investors of the other Contracting Party who are owners of those shares." "Article 9 Investment Disputes (1) Any dispute between an investor of one Contracting Party and the other Contracting Party in connection with an investment in the territory of the other Contracting Party shall..." " Article 12 Prohibitions and Restrictions Nothing in this Agreement shall prevent either Contracting Party from applying prohibitions or restrictions to the extent necessary for the protection of its essential security interests, or for the prevention of diseases and pests in animals or plants." B.b. Le 2 septembre 2013, X.________, se basant sur la clause arbitrale incluse dans le TBI, a introduit une procédure d'arbitrage contre l'Inde en vue d'obtenir le paiement de dommages-intérêts pour cause de violation des art. 3 et 5 du TBI. Un tribunal arbitral de trois membres a été constitué, conformément au Règlement d'arbitrage de la Commission des Nations Unies pour le droit commercial international (CNUDCI), sous l'égide de la Cour permanente d'arbitrage (CPA), et son siège fixé à Genève. L'anglais a été désigné comme langue de l'arbitrage. L'Inde a soulevé trois objections préliminaires, lesquelles, à l'en croire, empêchaient la demanderesse d'initier cet arbitrage: elle a fait valoir, en premier lieu, que le TBI ne protège que les investisseurs ayant effectué directement des investissements en Inde, ce qui ne serait pas le cas de X.________ puisque la société allemande avait à dessein structuré son investissement sous la forme d'un apport de fonds à sa filiale de Singapour, celle-ci ayant ensuite investi ces fonds dans A.________; la défenderesse a soutenu, en deuxième lieu, que toutes les activités déployées par X.________, via sa filiale, en étaient restées au stade des préparatifs, si bien qu'elles ne constituaient que des préinvestissements non protégés par le TBI; en troisième lieu, elle a dénié à X.________ le droit de se prévaloir des règles matérielles du traité, étant donné que les mesures incriminées étaient nécessaires à la protection de ses "intérêts essentiels de sécurité", réservée par l'art. 12 du TBI. Le Tribunal arbitral a accepté de restreindre, dans un premier temps, la procédure au traitement des questions de sa compétence et du principe de la responsabilité de la défenderesse, pour n'examiner qu'ensuite, le cas échéant, le problème de la quantification des dommages-intérêts réclamés par la demanderesse. Par sentence intérimaire du 13 décembre 2017, il s'est déclaré compétent pour connaître du litige divisant les parties, a constaté que l'Inde avait violé le standard du traitement juste et équitable ( Fair and Equitable Treatment) au sens de l'art. 3 (2) du TBI et a indiqué qu'il prendrait les dispositions nécessaires pour la continuation de la procédure désormais centrée sur le calcul du dommage. Les arguments de fait et de droit qui étayent cette sentence seront mentionnés plus loin, en tant que de besoin, dans le cadre de l'analyse des critiques dont ils font l'objet devant la Cour de céans.