Originally from Take the Witness: Cross-Examination in International Arbitration, 2d Ed.

Investment arbitration concerns the resolution of disputes between foreign investors and host states arising under bilateral or multilateral investment treaties.  These arbitrations may be ad hoc, or they may take place under institutional rules such as the ICSID Convention or the UNCITRAL Rules.  Investment arbitration is different from international commercial arbitration, which concerns the resolution of disputes between parties from two countries arising under their commercial contracts and their arbitration agreement, which is often contained in the dispute resolution clauses of the contract.

Both investment arbitration and international commercial arbitration provide for hearings, except in exceptional situations where hearings are dispensed with by the tribunal or mutual consent of the parties.  At these hearings, the parties present their oral arguments in opening and closing statements.  The main evidentiary function of these hearings, however, is to question witnesses.  Therefore, cross-examination features prominently in investment arbitration as it does in international commercial arbitration.

While there are special considerations for cross-examination in investment arbitration, which are addressed later in this chapter, it is useful to begin by setting forth certain fundamental principles that are common to both investment arbitration and international commercial arbitration.