International investment law (IIL) provides great protection to corporations through over 3000 treaties, national laws, and state-investor contracts. Corporations often do not need to exhaust domestic remedies, and the decisions of arbitrators may not be reviewed when the company seeks to enforce the decision... International human rights law and IIL can be complementarity, but conflicts have arisen, [such as where] a state adopts measures that negatively impact on investment law protections in order to secure human rights [or]... when businesses negatively impact on human rights and the state seeks to hold the business accountable through IIL.

A lack of policy coherence and inter-agency cooperation within domestic systems has long prevented the inclusion and protection of IHRL through IIL. But, there is... a great model for doing this. Last December, Morocco and Nigeria signed a bilateral investment treaty... that will oblige both states to ensure their “laws, policies, and regulations are consistent with the international human rights agreements to which they are a Party,”... [and] requires foreign corporations (and other investors) who are beneficiaries of the IIL treaty to “uphold human rights in the host state.”

IIL tribunals have made it clear that if states want to ensure businesses are bound by IHRL, they need to say so within their IIL treaties, domestic laws, and contracts. The Morocco-Nigeria BIT gives a great example of how this can happen. As new IIL treaties are being negotiated, states should ensure the UNGP are reflected.