650. International trade interests are considered to be involved in arbitration proceedings if, among other possibilities, the parties to the arbitration agreement have, at the time of the conclusion of that agreement, their places of business in different States or if the place where they choose to conduct the arbitration is outside the State in which they have their places of business. Such interests are also considered to be involved in arbitration proceedings if the place where a substantial part of the obligations of the commercial relationship is to be performed, or the place with which the subject matter of the dispute is most closely connected, is outside the State in which they have their places of business, or if the parties have expressly agreed that the subject matter of the arbitration agreement relates to more than one State.