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1. No Contracting State shall be bound by this Convention to afford transit to persons whose admission into its territory is forbidden, or for goods of a kind of which the importation is prohibited, either on grounds of public morals, public health or security, or as a precaution against diseases of animals or plants or against pests.
2. Each Contracting State shall be entitled to take reasonable precautions and measures to ensure that persons and goods, particularly goods which are the subject of a monopoly, are really in transit, and that the means of transport are really used for the passage of such goods, as well as to protect the safety of the routes and means of communication.
3. Nothing in this Convention shall affect the measures which a Contracting State may be called upon to take in pursuance of provisions in a general international convention, whether of a worldwide or regional character, to which it is a party, whether such convention was already concluded on the date of this Convention or is concluded later, when such provisions relate:
(a) to export or import or transit of particular kinds of articles such as narcotics, or other dangerous drugs, or arms; or
(b) to protection of industrial, literary or artistic property, or protection of trade names, and indications of source or appellations of origin, and the suppression of unfair competition.
4. Nothing in this Convention shall prevent any Contracting State from taking any action necessary for the protection of its essential security interests.