External voting can often be controversial. For example, opposition parties may claim that it is being used by the incumbents in support of the governing parties, either by allowing (or not allowing) the external vote, or because in the way the process is implemented, which may not be seen to be sufficiently transparent.

If an election is being observed, an assessment of the external voting is an integral part of the process. That does not, however, mean that the process needs to be assessed by observers at every step, even if this is practically possible. One example would be the external voting in Croatia. Shortly before the legislative elections in 1995 the election law was amended to include 12 members of the parliament to be elected by Croatians living abroad. The citizenship law permitted any ethnic Croat to obtain Croatian citizenship without having a family or territorial connection to the Republic of Croatia and without having any intention to move to Croatia. The only condition was that the person issued a written statement stating ‘that he or she considers himself or herself to be a Croatian citizen’. The result and intention of the rule were that more than 300,000 Croats from neighbouring Bosnia and Herzegovina acquired Croatian citizenship and were given the right to vote. The opposition claimed that the incumbents allowed this trusting that the Croats in Herzegovina would vote in favour of nationalistic parties. The political and legal conditions for the external voting were therefore more important than the technical conduct of the election.

For the Croatian presidential elections in 1997, the OSCE/ODIHR decided not to observe the external voting. The voting took place in polling stations across Herzegovina and some other cities in Bosnia and Herzegovina and, with an OSCE mission well established in Bosnia and Herzegovina, a high-quality observation operation would have been possible to organize. Given the general framework and the unusual (and, seen from Bosnia and Herzegovina, one would argue, unfriendly) citizenship rules, the main issue was not how the elections were carried out, but rather that they were allowed to happen at all.

For the Croatian legislative elections in 2000, the external voting was observed by the OSCE/ODIHR, partly because there was some development in the discussions between Croatia and Bosnia and Herzegovina regarding the citizenship issue, and partly because the parties to the discussions wanted this part of the process to be observed as well.

Even if there is general agreement on allowing external voting, the process itself may be difficult to observe. External votes are often not cast in person, and the arrangements can cover a large geographical area. The considerations regarding the observation of external voting would therefore involve logistical and practical issues. In the end it is important that an observation mission does not draw conclusions that cannot be substantiated by the evidence that has been collected from the process.