This is the list of countries that border only one other country, with only land borders being counted
Country,Neighbour,Border length (km),Border length (mi)Brunei,Malaysia,381,237Canada,United States,"8,893","5,526"Denmark,Germany,68,42Dominican Republic,Haiti,360,220The Gambia,Senegal,740,460Haiti,Dominican Republic,360,220Ireland,United Kingdom,360,220Lesotho,South Africa,909,565Monaco,France,4.4,2.7Papua New Guinea,Indonesia,820,510Portugal,Spain,"1,214",754Qatar,Saudi Arabia,60,37San Marino,Italy,39,24South Korea,North Korea,238,148Timor-Leste,Indonesia,228,142United Kingdom,Ireland,360,220Vatican City,Italy,3.2,2,,,www.downloadexcelfiles.com,,,