Name a country that borders exactly one other country, disregarding water borders.

The only reason that there were followups at all was because of debate
over the definition of "country".  If I had explicitly defined it to mean
"sovereign state", which is what I was intending, the complete list would
have been:

         Brunei              [Malaysia]
         Canada              [United States]
         Denmark             [Germany]
         Dominican Republic  [Haiti]
         Gambia              [Senegal]
         Haiti               [Dominican Republic]
         Ireland             [United Kingdom]
         Lesotho             [South Africa]
         Monaco              [France]
         Papua New Guinea    [Indonesia]
         Portugal            [Spain]
         Qatar               [possible*]
         San Marino          [Italy]
         South Korea         [North Korea]
         United Kingdom      [Ireland]
         Vatican City        [Italy]

* The Saudi Arabia - United Arab Emirates border is undemarcated.
  Some maps show both countries bordering Qatar; others show only Saudi
  Arabia doing so; older maps show only the UAE doing so.

"Water border" was also a loose phrasing, as it was not meant to include
river borders, but that turned out not to matter.

> But you have mentioned "only one land border", while others I think have
> talked about "only one land neighbour".  The two are different.  Canada,
> for instance, has only one land neighbour, but five land borders.

True for a suitable definition of "a land border"; Canada borders on all
four mutually disconnected pieces of the mainland US (Point Roberts WA,
Northwest Angle MN, mainland AK, and the big piece), and the border with
the Northwest Angle is interposed between two segments of border with the
big piece.  On the other hand, if "a land border" means a section of
border that does not run through a lake or seawater, or if it means this
with the additional requirement that it does not follow a river, then
there are quite a few more "land borders" to Canada, and it's not
particularly interesting to count them.  (This means I started to do so
and got bored.)

-- Mark Brader <msb@sq.com> (1996; the question was part of a Rare
   Entries contest)

There was also discussion recently of countries other than the US
having a border with Canada.  I don't think anyone mentioned Point
Pleasant Park in Halifax, Nova Scotia.  The park makes up the tip of
the peninsula that most of Halifax occupies, but as I understand it, it
is still nominally part of Great Britain, and only leased by the city.
It was apparently not granted, somehow, when Canada became independent
in 1867.  I've heard this story several times, and it always sounds
unlikely - but on the other hand there is a regular ceremony at which
the "rent" (a shilling a year, I think) is handed over.

-- Steve <scoughla@kilcom1.ucis.dal.ca>