The Belgian request is based on the treaty of 1839, and the Iron Rhine Treaty of 1873. Critics felt that Belgium could not invoke these treaties, as the 1873 treaty granted Belgium a concession of 99 years on the Iron Rhine route, a period which ended in 1972. Furthermore, Belgium had sold the railroad to the Dutch Government. The argument that carries most weight in the Netherlands is that the railroad runs through the nature reserve of De Meinweg, and nature activists fear the destruction of the local habitat of several threatened species, whereas Belgian interests consider this to be a delaying tactic while the Netherlands completes the Betuwe line.