Foreign investors benefit from investment protection standards in international investment law which are enforceable in investment arbitration. However, international law does not directly bind foreign investors and investment arbitration struggles to address foreign investor misconduct. Thus, host States cannot easily claim against foreign investors for breaches of international law in investment arbitration. In Counterclaims in Investment Arbitration, Edward Guntrip illustrates how host States can use counterclaim procedures in investment arbitration to hold foreign investors accountable for misconduct that breaches international law. Based on arbitral practice, the book sets out how host States can amend their State practice and litigation strategies to enhance the effectiveness of counterclaim procedures and assesses when host States should take this course of action.