Reference to a 1946 Washington Treaty cannot be found. Perhaps you are referring to the Oregon Treaty, which was signed in Washington, D.C. on June 15, 1846. The Treaty of Oregan ended the boundary dispute concerning the Oregon Country, which had been occupied by Britain and US since the Treaty of 1818.
Deindustrialization caused a shift toward a service-based economy in the 1970's. Deindustrialization is the process of social or economic change due to a reduction in industrial activity.