Cambodia-Laos: Cambodia is concerned that Laos' extensive upstream dam construction will affect Cambodian waters downstream

Cambodia-Thailand: Cambodia and Thailand have agreed to maintain peace along the border regardless of the decision of the International Court of Justice (ICJ) over territorial dispute near Cambodia's Preah Vihear Temple; the ICJ decision of 11 November 2013 determined that Cambodia had sovereignty over the whole territory of the promontory of Preah Vihear; the border disputes do not involve large amounts of territory, and most of the issues were settled by the Nov. 11, 2013 ICJ ruling

Cambodia-Vietnam: issues include casinos built in Cambodia near the border (gambling and prostitution); narcotics (criminals, crime, and abuse); trafficking of women and children, petrol smuggling into Cambodia from Vietnam, illegal logging, and illegal migration

Ethiopia-Eritrea: Eritrea and Ethiopia agreed to abide by the 2002 Eritrea-Ethiopia Boundary Commission's (EEBC) delimitation decision, but neither party responded to the revised line detailed in the November 2006 EEBC Demarcation Statement

Ethiopia-Somalia: the undemarcated former British administrative line has little meaning as a political separation to rival clans within Ethiopia's Ogaden (populated largely by ethnic Somalis) and southern Somalia's Oromo region; the Somalia-based terrorist group al-Shabaab has conducted cross-border assaults into Ethiopia as recently as 2022

Ethiopia-South Sudan: while border clashes continue in the al-Fashqa (Fashaga) area, the US views the 1902 boundary treaty between Ethiopia and Sudan as being in force

Ethiopia-Sudan: Ethiopia's construction of a large dam (the Grand Ethiopian Renaissance Dam) on the Blue Nile in northern Ethiopia since 2011 has become a focal point of relations with Egypt and Sudan; Egypt has described the giant hydroelectric project as an existential threat because of its potential to control the flow of the river that is a key source of water for the country; Ethiopia completed filling the dam in 2023

Russia and Estonia in May 2005 signed a technical border agreement, but Russia in June 2005 recalled its signature after the Estonian parliament added to its domestic ratification act a historical preamble referencing the Soviet occupation and Estonia's pre-war borders under the 1920 Treaty of Tartu; Russia contends that the preamble allows Estonia to make territorial claims on Russia in the future, while Estonian officials deny that the preamble has any legal impact on the treaty text; Russia demands better treatment of the Russian-speaking population in Estonia; as a member state that forms part of the EU's external border, Estonia implements strict Schengen border rules with Russia