The German–Polish declaration of non-aggression (, ), also known as the German–Polish non-aggression pact, was a non-aggression agreement between Nazi Germany and the Second Polish Republic that was signed on 26 January 1934 in Berlin. Both countries pledged to resolve their problems by bilateral negotiations and to forgo armed conflict for a period of 10 years. The agreement effectively normalised relations between Poland and Germany, which had been strained by border disputes arising from the territorial settlement in the Treaty of Versailles. Germany effectively recognised Poland's borders and moved to end an economically-damaging customs war between the two countries that had taken place over the previous decade. Background Before 1933, Poland had worried that some sort of alliance would take place between German Weimar Republic and the Soviet Union to the detriment of Poland. Therefore, Poland made a military alliance with France in 1921. Because the Nazis and the Communists were bitter enemies, a hostile Soviet-German alliance after Hitler came to power in 1933 seemed very unlikely. In 1925, under the Locarno treaties, it was agreed that France would never send forces into Germany outside of its own occupation zone in the Rhineland and that both Britain and Italy would guarantee the Franco-German border against any attempt to change it from either side. The purpose of the Locarno treaties was to make it impossible for France to occupy the Ruhr as had happened in 1923. From the Polish perspective, the Locarno treaties were a diplomatic disaster, as Britain and Italy refused to make the same guarantees for Germany's eastern border while theoretically both Britain and Italy would declare war on France if the French should move French Army troops into Germany beyond the Rhineland. Under the terms of the Franco-Polish defensive alliance of 1921, France was supposed to start an offensive from the Rhineland occupation zone into the north German plain if Germany should invade Poland, but the Locarno treaties had effectively gutted the provisions of the Franco-Polish alliance. The British Foreign Secretary Austen Chamberlain had pushed for the Locarno treaties as a way for Germany to peacefully revise the Treaty of Versailles in eastern Europe. Chamberlain believed that as long as the Poles had a great power like France as their ally, they would never hand over the areas that Germany was claiming such as the Polish Corridor and Upper Silesia, but if Franco-German relations improved, then that would