... were so careless (or lazy, or understaffed) that they did not bother doing proper surveying and marking of the borders between jurisdictions. (In the foreward to the second edition of "The Dictionary of Imaginary Places", Alberto Manguel describes a situation in West Africa where the team fudged in measurements for one particular location ... not on a present-day national border, but one can imagine this sort of thing occurring elsewhere.) In an earlier time when both territories may have "belonged" to the same mother country, this was not a major issue -- but when they became independent, sometimes these ambiguous areas became major sources of conflict between the neighboring countries. For example, the border between Ethiopia and Eritrea. The authorities were supposed to clear it up at a later date, but never got around to it, so now the local people are stuck with the situation and the UN has a costly problem on its hands.
"Badme (alternatively spelt Badime, Baduma, or Badame) is the name given to
the region that includes the contested territory.
But Badme is also a village - or possibly even two villages. Neither side
has pinpointed the exact location of the Badme which is supposedly the point
of contention."
http://www.somaliawatch.org/Archivemay/000512101.htmhttp://news.bbc.co.uk/2/hi/africa/1943527.stmEven the US and Canada have had border disputes over confusing or not-clearly-defined areas. And then there is the notorious case where the surveyors were supposedly drunk (apparently not true -- just working with primitive equipment) and put the border through existing towns.
http://www.tomifobia.com/border_lines/growth.htmlhttp://www.townshipsheritage.com/Eng/Hist/Law/border.htmlIn North America, the straight lines marking many provinces and states often divided up existing aboriginal territories, just like in colonial Africa ... even though there have not been major all-out wars triggered by this, it's definitely contributed to the problems faced by Indian bands. For example, the Mohawk nation is divided between Ontario, Quebec, and New York State -- this makes it very difficult to administrate, and the band membership is fragmented. People who are in need of assistance frequently get overlooked by the various social-service agencies, which assume "it's someone else's problem".