By far the gravest menace to Poland's longevity came from abroad, not from internal weaknesses. The center of Poland's postwar foreign policy was a political and military alliance with France, which guaranteed Poland's independence and territorial integrity. Although Poland attempted to join the Little Entente, the French-sponsored alliance of Czechoslovakia, Romania, and Yugoslavia, Czechoslovak suspicions of Polish territorial ambitions prevented Polish membership. Beginning in 1926, Pilsudski's main foreign policy aim was balancing Poland's still powerful neighbors, the Soviet Union and Germany. Pilsudski assumed that both powers wished to regain the Polish territory lost in World War I. Therefore, his approach was to avoid Polish dependence on either power. Above all, Pilsudski sought to avoid taking positions that might cause the two countries to take concerted action against Poland. Accordingly, Poland signed nonaggression pacts with both countries in the early 1930s. After Pilsudski's death, his foreign minister Józef Beck continued this policy.

The failure to establish planned alliances in Eastern Europe meant great reliance on the French, whose enthusiasm for intervention in the region waned markedly after World War I. The Locarno Pact, signed in 1926 by the major West European powers with the aim of guaranteeing peace in the region, contained no guarantee of Poland's western border. Over the next ten years, substantial friction arose between Poland and France over Polish refusal to compromise with the Germans and French refusal to resist Adolf Hitler's rise to power in the early 1930s. The Polish nonaggression treaties with Germany and the Soviet Union resulted from this bilateral deterioration of confidence.

The Polish predicament worsened in the 1930s with the advent of Hitler's openly expansionist Nazi regime in Germany and the obvious waning of France's resolve to defend its East European allies. Pilsudski retained the French connection but had progressively less faith in its usefulness. As the decade drew to an end, Poland's policy of equilibrium between potential enemies was failing. Complete Nazi occupation of Czechoslovakia in early 1939 encircled Poland on three sides (East Prussia to the northeast had remained German). Hitler's next move was obvious. By 1939 Hitler had shattered the continental balance of power by a concerted campaign of armed diplomatic extortion that brought most of Central Europe into his grasp.

Data as of October 1992