a demilitarised border zone operated by the United Nations Peacekeeping Force in Cyprus operate and patrol within the buffer zone. The buffer zone was established in 1974 due to ethnic tensions between Greek and Turkish Cypriots. The green line is similar in nature to the 38th parallel separating the Republic of Korea and North Korea. Some border zones, referred to as border vistas, are composed of legally mandated cleared space between two areas of foliage located at an international border intended to provide a clear demarcation line between two jurisdictions. Border vistas are most commonly found along undefended international boundary lines, where border security is not as much of a necessity and a built barrier is undesired, and are a treaty requirement for certain borders. An example of a border vista is a cleared space around unguarded portions of the Canada–United States border. Similar clearings along the border line are provided for by many international treaties. For example, the 2006 border management treaty between Russia and China provides for a cleared strip along the two nations' border. Immigration law and policy Immigration law refers to the national statutes, regulations, and legal precedents governing immigration into and deportation from a country. Strictly speaking, it is distinct from other matters such as naturalisation and citizenship, although they are often conflated. Immigration laws vary around the world, as well as according to the social and political climate of the times, as acceptance of immigrants sways from the widely inclusive to the deeply nationalist and isolationist. Countries frequently maintain laws which regulate both the rights of entry and exit as well as internal rights, such as the duration of stay, freedom of movement, and the right to participate in commerce or government. National laws regarding the immigration of citizens of that country are regulated by international law. While the United Nations' International Covenant on Civil and Political Rights mandates that all countries allow entry to their own citizens, this principle is not always respected in practice. For instance, during the COVID-19 pandemic, Australia adopted a policy of denying entry to all individuals in particularly affected jurisdictions, including Australian citizens and permanent residents. Similarly, while states within the Schengen Area typically permit freedom of movement across borders, many states within the area implemented ad hoc border controls during the pandemic. Immigration policy is the aspect of border control concerning the transit of people into a