To answer the research questions, it is necessary to describe cross-country and cross-border pipelines and their technical specifications. Part I of this thesis focuses on general issues on which the whole thesis will be based. More specifically, it is necessary to legally define the research subject. The definitions of pipelines, the stakeholders and trans-boundary damage, which may be caused by such pipelines, will be presented in this Part. Furthermore, the legal regime governing the construction and operation of pipelines will also be proposed here. Therefore, Part I of the thesis deals with the issues that must be clarified before the main arguments are presented in Parts II & III.

Chapter 2 provides general features of cross-border oil and gas pipelines. Pipelines, their role in providing global energy trade and their growing importance in transporting energy from source areas to demand areas will be respectively discussed. Various types of pipelines will be defined in Chapter 2. Furthermore, a brief overview of stakeholders who influence the pipeline project or are influenced by the pipeline project will be presented. After having an overview of the pipelines, it is necessary to define trans-boundary damage. Chapter 3 defines risks and harm related to the construction and operation of pipelines. In doing so, first the actual risks accompanying pipelines will be discussed by analysing reports gathered concerning cross border and cross-country pipeline accidents. Second, building upon pipeline accidents reports as well as literature, the harm related to oil and gas pipelines, including personal injury, damage to the environment and property damage will be elaborated. An attempt will be made to draw a clear portrait of trans-boundary damage which may be caused by pipelines. This will be done by looking at accident reports concerning the actual occurrence of trans-boundary damage which has been caused by pipelines.

The legal regime in this thesis includes a body of rules with respect to the operation and construction of oil and gas pipelines as well as the prevention and compensation of trans-boundary damage. Therefore, the prevention and compensation of trans-boundary damage which may be caused by pipelines depends on the applicable legal regime as will be introduced in the thesis.