A report by François Dubuisson, professor in international law at the Université libre de Bruxelles, dated February 2014 outlines three legal obligations for third states :
To ensure respect for international humanitarian law : the EU, France and Belgium must take the necessary measures to ensure that Israel respects the prohibition on the establishment of settlements.
To not recognize as legal an illegal situation : the EU, France and Belgium cannot develop economic relations with Israel which would recognize Israel’s authority over the Palestinian territories or which would give legal effect to the settlements’ activities.
To not render aid or assistance in maintaining an illegal situation : the EU, France and Belgium cannot maintain commercial and economic relations with the settlements if those relations contribute to their economic prosperity.
In relation to Israel’s settlement policy, Belgium and France must :
ensure that their policy does not directly or indirectly contribute to the consolidation or expansion of the settlements ;
take measures to sever all ties between their economy and the Israeli settlement economy.