In the past there was strong support for the rule of non-responsibility according to which
one State of nationality might not bring a claim in respect of a dual national against another State
of nationality. The 1930 Hague Convention on Certain Questions Relating to the Conflict of
Nationality Laws declares in article 4 that:
“A State may not afford diplomatic protection to one of its nationals against a State
whose nationality such person also possesses.”73
Later codification proposals adopted a similar approach74 and there was also support for this
position in arbitral awards.75 In 1949 in its advisory opinion in the case concerning Reparation
for Injuries, the International Court of Justice described the practice of States not to protect their
nationals against another State of nationality as “the ordinary practice”.76