If, within three months from the date of the notification referred to in Article 23, paragraph 2
, either party fails to make the nomination referred to in paragraph 1 above, the choice of the arbitrator shall, on request of the other party, be made by the President of the International Court of Justice from the persons included in the said panel. This shall also apply, when so requested by either party, if within one month from the date of appointment of the second arbitrator, the first two arbitrators are unable to agree on the nomination of the third arbitrator. However, if, in these two cases, the President of the International Court of Justice is prevented from making the choice, or if he is a national of one of the States parties to the dispute, the Vice-President of the International Court of Justice shall make the aforementioned appointments, provided that he himself is not a national of one of the States parties to the dispute; if such is the case, the member of the International Court of Justice who is not a national of one of the States parties to the dispute and who has been chosen by the President or Vice-President shall make the appointments. A national of the State applying for arbitration may not be chosen to fill the post of the arbitrator whose appointment devolves on the Administrative Council nor may a person included in the panel and appointed by the Administrative Council be chosen to fill the post of an arbitrator whose appointment devolves on the State which is the claimant. Nor may a person of either of these categories be chosen as chairman of the Tribunal.