In a previous post, I asked:
Which judges of the ICJ had served as ad hoc judges at the ICJ prior to their election to the ICJ?
Wim Muller was very quick off the mark in noting that on the ICJ current bench, Bernardo Sepúlveda-Amor (Mexico) was an ad hoc judge in the Avena case (Mexico v. USA) before being elected to the Court. Thanks to Martin Cabrera for also noting that Judge Antônio Cançado Trindade was also an ad hoc judge in the Dispute regarding Navigational and Related Rights (Costa Rica v. Nicaragua) case before his election to the Court. If one includes Gaja (who joins in February), five of the Judges on the current bench had previously served as ad hoc judges. Apart from Gaja, Antônio Cançado Trindade and Sepúlveda-Amor, the other two are:
-Judge Mohamed Benouna [Frontier Dispute (Benin/Niger]; and
Judge Yusuf in the Certain Questions of Mutual Assistance in Criminal Matters (Djibouti v. France)
What is interesting is that by my reckoning, apart from these 5 current judges, there had previously only been seven other judges who had served as ad hoc judges before they were elected to the Court. Thanks to Martin Cabrera for pointing out two of them: They are (1) Judge Roberto Ago (Italy) in the Arbitral Award (Honduras v. Spain) (2) Judge Federico de Castro in the Barcelona Traction case (I have to admit I missed him out on the list I had constructed). The others are (3) Judge Evensen (Norway) in Continental Shelf (Tunisia/Libya); (4) Judge Mosler (Germany) in North Sea Continental Shelf cases; (5) Judge Nagendra Singh (India) in the ICAO Council Case (India v. Pakistan) ; (6) Judge Jean Spiropoulous (Greece) in the Ambatielos Case (Greece v. UK); and (7) Judge Muhammad Zafrulla Khan in the SouthWest African Cases and the Trial of Prisoners of War case (Pakistan v. India). Readers, have I missed any out?
It is interesting to note that it is now much more common than was previously the case for ICJ judges not only to have previous experience on another international tribunal but also to have prior experience as an ad hoc Judge at the ICJ. Why might this be so? With regard to experience on prior international tribunals the answer probably lies in the fact that there are more international tribunals than was previously the case. But what about prior experience as an ad joc judge? Is it just the case that States now value prior judicial experience than they previously did. To answer that question one might have to consider which candidates who had been ad hoc judges were not elected (there have been some). Perhaps the answer lies in the fact that there are now more ICJ cases than was the case before meaning that more candidates for election to the ICJ have experience of being an ad hoc judge.