All too often, a Statee E -s obligation to protect the health and safety of its citizens is hampered by the rights of foreign investors under investment treaties, usually enshrined in arbitration clauses. States compete for foreign investment with the perception that it will accelerate their economic development. However, the realisation of this goal is increasingly eroded by disputes that pit the host Statese E – sovereign duty to regulate businesses in the public interest against foreign companiese E – treaty rights to protect their investments. Moreover, international investment law often conflicts inescapably with human rights law, environmental law, and EU law, all of which are also primarily premised on treaties. Great normative ambivalence ensues, posing serious challenges to the legitimacy and utility of the investor-State arbitral system.