An unexpected situation arose that modified the political relations of the nations of the Pacific: the war declared by Spain on Peru and Spain's reassertion of her claims to the Chincha islands. The Governments of the Pacific were alarmed, and Chile, Bolivia and Ecuador made common cause with Peru. Previous differences were considered as being of secondary importance, and Bolivia and Chile sought to end the border conflict. Interrupted diplomatic relations were resumed, and on 10 August 1866 the Boundary Treaty was signed in Santiago.