To complete this logic puzzle, you'll need basic knowledge of country trivia, such as country names, relative populations, borders, and capitals. The solution is possible to find without guessing.
"Adjacent" refers to neighboring cells, including diagonally.... Countries belong to continents according to general Sporcle standards (i.e. Russia is European). All countries are referred to by their Sporcle-standard names (e.g. Cote d'Ivoire, Timor-Leste. Note that there are no countries starting with 'the').... by definition, an "island nation" has zero land borders.