Serious discussions of on-site inspection as a mechanism to verify compliance with the provisions of arms control agreements developed only in the period after World War II. Prior to that time, arms control agreements, such as the Rush-Bagot Treaty of 1817 between the United States and Great Britain regulating the number of warships on the Great Lakes and the naval and chemical weapons treaties negotiated in the period between the two world wars, contained virtually no verification provisions. They were, in essence, “gentlemen's agreements” to refrain from prohibited activities. Compliance problems that arose in connection with such agreements were handled as broader foreign policy issues.
A major peace treaty—the 1919 Treaty of Versailles terminating World War I—did contain a number of verification provisions, including on-site inspections, designed primarily to ensure the payment of reparations and restrict the regrowth of German military power. Among the treaty's provisions were measures to demilitarize the Rhineland and to impose a number of military reduction and production restrictions. To verify compliance with these provisions, the treaty set up three inter-allied control commissions—one each for land, air and naval services—to carry out on-site inspection activities. These relatively small (less than 1,500 personnel in total) multinational commissions were made up of military officers and noncommissioned officers drawn from combat and intelligence units. They were headquartered in Berlin, but inspectors were authorized to exercise their rights to travel in any part of Germany. During the period between 1920 and 1927, these commissions scheduled and carried out frequent on-site inspections of Germany's armed forces. They monitored and reported on the treaty-mandated destruction and demobilization of German weapons, personnel, fortifications, and facilities and the treaty provisions prohibiting the manufacture, testing and development of modern military weapons. 1 The demilitarization provisions of the Versailles Treaty, however,