AS/Jur (2023) 17 59. Last but not least, the Convention imposes in some circumstances a duty on States to cooperate effectively with each other, particularly in transnational cases involving serious breaches of human rights, such as unlawful killings,91 human trafficking92 or sexual abuse of children.93 This duty implies at the same time an obligation to seek assistance and an obligation to afford assistance and is part of the procedural obligation arising under Articles 2, 3 and 4 of the Convention. Therefore, in cases of transnational repression the duty to cooperate in the investigation of the alleged breach is all the more important (see the Carter case, mentioned above94). 60. In conclusion, the Court’s case-law provides sufficient examples to delineate the principles of State responsibility for transnational repression, even if the Court has never used this term in its judgments. Applying the Court’s case-law, a jurisdictional link should be established between an act of transnational repression and the persecuting State to determine the responsibility under the Convention. Only then a violation of the Convention could be found, which could take various forms from serious human rights violations (killings, kidnappings, enforced disappearances, renditions, arbitrary detentions, etc.) to associated violations of privacy, freedom of expression, freedom of movement, etc. In this context, the Court may also examine the responsibility of host States on whose territories the acts of transnational repression occurred. These States may therefore have positive obligations under the Convention to protect potential victims from acts of transnational repression and prevent them from occurring. In the end, all Contracting States have a collective duty to cooperate in the investigation of serious human rights violations and, therefore, fight against impunity for acts of transnational repression committed on European soil. 4.2. The Parliamentary Assembly 61. The most relevant resolutions and reports of the Assembly, which could be relevant for codifying and developing principles in the fight against transnational repression, are the following:     Resolution 2315(2019) “Interpol reform and extradition proceedings: building trust by fighting abuse”, which recalls the need for transparent international cooperation in criminal law; Resolution 2252 (2019) “Sergei Magnitsky and beyond – fighting impunity by targeted sanctions”, which called upon member States to consider enacting legal instruments enabling their government to impose targeted sanctions on individuals reasonably believed to be personally responsible for serious human rights violations for which they enjoy impunity on political grounds or owing to corrupt practices; Resolution 2161 (2017) “Abusive use of the Interpol system: the need for more stringent legal safeguards”, in which the Assembly expressed concerns over the abuse by certain governments of the ‘Red Notice’ system in order to persecute members of the political opposition beyond their borders; Resolution 2187 (2017) “the Venice Commission’s Rule of Law Checklist”, which encourages wider and more systematic use of the Venice Commission Checklist to ensure conformity with basic principles of the rule of law; 62. A report on “Pegasus and similar spyware and secret state surveillance” is also underway. Some valuable ideas to fight and prevent transnational repression can be found in all these reports and resolutions. In Resolution 2315 (2019), the Assembly welcomed the fact that Interpol had implemented many recommendations made by the Assembly in its 2017 report aimed at strengthening the Interpol system and fighting the abuse of Red Notices and Diffusions. However, it stated that further work still needed to be done to improve the transparency of Interpol and to strengthen the accountability of States who frequently abuse Interpol’s instruments. For instance, Interpol should further improve preventive and subsequent scrutiny of Red Notices and wanted person diffusions; further strengthen the appeals procedure before the Commission for the Control of Interpol’s Files (CCF); consider setting up an independent appeals body against the decisions of the CCF such as an ombudsperson; and set up a compensation fund for victims of unjustified Red Notices and wanted person diffusions. The Assembly also called on member States to take a set of measures to 91 Güzelyurtlu and others v. Cyprus and Turkey [GC], No. 36925/07, 29 January 2019, pars. 229-236; Romeo Castaño v Belgium, No 8351/17, 9 July 2019. 92 Rantsev v. Cyprus and Russia, op.cit. 93 X and Others v. Bulgaria [GC], No. 22457/16, 2 February 2021, pars .191 and 217-220. 94 While the Court could not examine whether the UK authorities had complied with their obligation to cooperate with their Russian counterparts (the application was only directed against Russia), it observed that the Russian authorities had attempted to thwart the efforts of the British investigators to establish the facts of the case (paragraphs 144 and 146). 19