Further surveys, military missions and expeditions followed, which helped to create the strategic and logistical framework for the successful French colonial acquisition of Tonkin and Annam in 1884, culminating in the establishment of the Indochinese Union in 1887, territorial losses for Siam, and the Treaty of Bangkok in 1893, which, among other things, resulted in the French protectorate over Laos and Cambodia as the Mekong constituted the border between France and Siam over the course of almost 1500 kilometers .