ASEAN's external agreements take many different shapes. They come under different headings and they involve both ASEAN as a distinct entity and its ten Member States as parties on one side of the external agreement. The practice continues to show uncertainties, and it remains in flux.

We have structured our exposition of the internal effects of external agreements along the lines of three different types of such agreements: those with ASEAN as an international organisation as the party to the agreement (Chapter 6) and those that have ASEAN Member States as parties, as plurilateral agreements (Chapter 5) or, in a different reading, as joint agreements (Chapter 6). We have explored the internal effects broadly, to include direct and indirect legal effects as well as effects on the workings of the relationship between ASEAN and its members and between the members themselves. External agreements, we submit, have a bearing on all these relationships.

The overall assessment of the internal effects of ASEAN external agreements, first of all, needs to connect to the type of agreement. If it has the international organisation ASEAN alone as a party, our inquiry shows rather clearly that such agreements do not bind Member States. If members are not themselves parties to the agreement, they could only become bound by ASEAN agreements due to a provision to that effect in the Charter or in a similar document. While such a provision is lacking and cannot be seen on an even distant horizon, this does not conclude the question of internal effects within the ASEAN legal regime. Notably, we drew attention to members’ concurrent and subsidiary responsibility and indirect liability for actions of ASEAN as an IO. Should ASEAN incur financial obligations, for instance, by having to pay damages for a wrongful act, there is a compelling argument that members are indirectly liable.

We set out the internal effects of those external agreements, which clearly have the members themselves as a party, on the basis that this is a matter of both international and domestic law. The backdrop of the assessment here is the insight that general international law, in contrast to European law, does not demand to be given direct effect. That is not to question that domestic law cannot justify any acts that are internationally wrongful.