Whose international law is changing? The role of communities of practice

It is particularly tricky to identify the degree to which a change attempt has been successful: the same legal change may be registered by different communities of practice in different ways. For instance, arbiters relying on the idea of precedent on the one hand, and arbiters relying on the idea of case specific application of convention and/or bilateral investment treaties on the other hand may have diverging ideas of how investment law changed. Another example is the development of International Humanitarian Law that seems driven by a handful of states, a community of IHL-based practice that disregards other states’ practices capable of changing the laws of war. In sum, this paper looks at examples of communities of practice in IHL and Investment arbitration in order to demonstrate their role and impact on the construction and recognition of change in international law.