In internal politics, Piłsudski's coup entailed sweeping limitations on parliamentary government, as his Sanation regime (1926–1939) at times employing authoritarian methods sought to "restore public life to moral health". From 1928 the Sanation authorities were represented in the sphere of practical politics by the Non-partisan Bloc for Cooperation with the Government (BBWR). Popular support and an effective propaganda apparatus allowed Piłsudski to maintain his authoritarian powers, which could not be overruled by the president, who was appointed by Piłsudski, nor by the Sejm. The powers of the Sejm were curtailed by constitutional amendments introduced soon after the coup, on 2 August 1926. From 1926 to 1930, Piłsudski relied chiefly on propaganda to weaken the influence of opposition leaders.
The culmination of his dictatorial and supralegal policies came in the 1930s with the imprisonment and trial of certain political opponents (the Brest trials) on the eve of the 1930 legislative elections, and with the 1934 establishment of a prison for political prisoners at Bereza Kartuska (today Biaroza), where some prisoners were brutally mistreated. After the BBWR's 1930 victory, Piłsudski left most internal matters in the hands of his "colonels", while he himself concentrated on military and foreign affairs. He came under considerable criticism for his treatment of political opponents, and their 1930 arrest and imprisonment was internationally condemned and damaged Poland's reputation.
In the military sphere, Piłsudski, who had shown himself an accomplished military strategist in engineering the "Miracle at the Vistula", has been criticized by some for subsequently concentrating on personnel management and allegedly neglecting modernization of military strategy and equipment. His experiences in the Polish-Soviet War (1919–21) may have led him to overestimate the importance of cavalry and to neglect the development of armored and air forces. Others, however, contend that, particularly from the late 1920s, he did support the development of these military branches. The limitations on Poland's military modernization in this period may have been less doctrinal than financial.
Under Piłsudski, Poland maintained good relations with neighboring Romania, Hungary and Latvia. Relations were strained with Czechoslovakia, however, and were still worse with Lithuania. Relations with Weimar Germany and the Soviet Union varied over time, but during Piłsudski's tenure could for the most part be described as neutral.
Piłsudski's Promethean program, designed to weaken the Russian Empire and its successor state, the Soviet Union, by supporting nationalist independence movements of major non-Russian peoples dwelling in Russia and the Soviet Union, was coordinated from 1927 to the 1939 outbreak of World War II in Europe by the military intelligence officer, Edmund Charaszkiewicz. In the Interbellum, the Prometheist movement yielded few tangible results.
Piłsudski sought to maintain his country's independence in the international arena. Assisted by his protégé, Foreign Minister Józef Beck, he sought support for Poland in alliances with western powers such as France and the United Kingdom, and with friendly, if less powerful, neighbors such as Romania and Hungary.
A supporter of the Franco-Polish Military Alliance and the Polish-Romanian Alliance (part of the Little Entente), Piłsudski was disappointed by the French and British policy of appeasement evident in those countries' signing of the Locarno Treaties. Piłsudski therefore aimed also to maintain good relations with the Soviet Union and Germany; hence Poland signed non-aggression pacts with both its powerful neighbors: the 1932 Soviet-Polish Non-Aggression Pact, and the 1934 German-Polish Non-Aggression Pact. The two treaties were meant to strengthen Poland's position in the eyes of its allies and neighbors.
Party affiliation: PPS