As our societies face new challenges and make new demands from policies addressing international investment, there is a new urgency to profoundly reconsider treaties addressing investment. This paper was prepared originally as background for initial inter-governmental and public discussions at the OECD about future investment treaties as well as possible alternatives. The paper surveys potential roles for treaties addressing investment in (i) contributing to sustainable development and responsible business conduct; (ii) preserving and improving investment market access and liberalisation of investment, and facilitating FDI; (iii) regulating subsidised state-owned enterprises, competition in subsidies for investment, and digitalisation; and (iv) addressing the interests of treaty-covered and other investors in reasonable legal predictability and a level playing field, together with the need for policy space and public support for treaty policy. It considers potential use of more flexible and varied remedies and implementation mechanisms. A final section briefly considers treaty policies as governments and societies confront the urgent challenge of climate change.