CDL-AD(2006)009 - 34 - order to ensure respect for human rights, or their abuse might be advanced. In this respect, the Venice Commission recalls that the legal framework concerning foreign military bases on the territory of Council of Europe member States must enable the latter to exercise sufficient powers to fulfil their human rights obligations. 151. While mutual trust and economic and military co-operation amongst friendly States need to be encouraged, in granting foreign state aircraft authorisation for overflight, Council of Europe member States must secure respect for their human rights obligations. This means that they may have to consider whether it is necessary to insert new clauses, including the right to search, as a condition for diplomatic clearances in favour of State planes carrying prisoners. If there are reasonable grounds to believe that, in certain categories of cases, the human rights of certain passengers risk being violated, States must indeed make overflight permission conditional upon respect of express human rights clauses. Compliance with the procedures for obtaining diplomatic clearance must be strictly monitored; requests for overflight authorisation should provide sufficient information as to allow effective monitoring (for example, the identity and status (voluntary or involuntary passenger) of all persons on board and the destination of the flight as well as the final destination of each passenger). Whenever necessary, the right to search civil planes must be exercised. 152. With a view to discouraging repetition of abuse, any violations of civil aviation principles in relation to irregular transport of prisoners should be denounced, and brought to the attention of the competent authorities and eventually of the public. Council of Europe member States could bring possible breaches of the Chicago Convention before the Council of the International Civil Aviation Organisation pursuant to Article 54 of the Chicago Convention. 153. As regards the treaty obligations of Council of Europe member States, the Commission considers that there is no international obligation for them to allow irregular transfers of prisoners to or to grant unconditional overflight rights, for the purposes of fighting terrorism. In the Commission’s opinion, therefore, States must interpret and perform their treaty obligations, including those deriving from the NATO treaty and from military base agreements and SOFAs, where these are applicable, in a manner compatible with their human rights obligations. As regards notably the NATO treaty, the Commission stresses that this principle is expressed in Article 7 according to which “[t]his Treaty does not affect, and shall not be interpreted as affecting in any way the rights and obligations under the Charter [of the United Nations] of the Parties which are members of the United Nations.” Even if NATO member states have undertaken obligations concerning irregular transfer or unconditional overflight, the Commission recalls that if the breach of a treaty obligation is determined by the need to comply with a peremptory norm (jus cogens), it does not give rise to an internationally wrongful act. As underlined above (para. 43), the prohibition of torture is a peremptory norm.