Situated on the North European Plain between Germany and Russia, Poland has often played a pivotal role in European history. It dominated Central Europe in the seventeenth century, stretching from the Baltic Sea in the north to near the Black Sea in the south as part of a commonwealth with Lithuania. Two centuries later, it had disappeared off the map, partitioned between Austria, Prussia and Russia.

Like Germany in the west and Russia to the east, Poland largely lacks clear natural borders. The Baltic Sea coast and central plain are flat and have historically served as an invasion route, from Napoleon’s attempted conquest of Russia in 1812 and Adolf Hitler’s more successful attempt in 1941-42 to the Soviet Union’s defeat of Nazi Germany the other way around three years later.

The country’s two main rivers, the Oder and Vistula, facilitate east-west movement. Most large cities, including Gdańsk, Poznań, Wrocław and Warsaw — the capital — straddle it.

Poland’s only natural defenses are in the south. The Carpathian and Sudeten ranges offer some barrier but are not forbidding enough to altogether deter an invading force, such as when the Austrians moved across the mountains in 1809 in a futile attempt to take Warsaw from what was then a French puppet state. Nor are they so rugged as to frustrate economic development. Major cultural and industrial centers like Katowice and Kraków can be found in the Carpathians.

Given its geographical position in Europe, Poland’s fate is inextricably tied up with the intentions of its neighbors. When they are weak, such as Germany and Russia were in the seventeenth century, Poland can defend its independence and prosper. When its rivals are not only powerful but act together, Poland is doomed.

Most infamously, between 1772 and 1795, the Austrian, Prussian and Russian Empires conspired to progressively remove Poland from the map. (Napoleon briefly resurrected it as the Duchy of Warsaw from 1807 to 1815.) Poland was restored after World War I but divided up between Germany and Russia again in 1939. It emerged from the Second World War that its invasion triggered smaller and further to the west. At the 1945 Yalta Conference, Western leaders acceded in demands from Soviet leader Joseph Stalin that Poland’s Eastern Borderlands be incorporated into Russian-controlled Belarus, Lithuania and Ukraine. Some one million ethnic Poles were moved west by the Soviet authorities and forced to make a new life for themselves in lands that were once German. Millions of Germans, in turn, were expelled from areas like East Prussia, Farther Pomerania and Silesia. Many resettled in the newly-formed Federal Republic of Germany.

Fearful of another invasion from the west, Russia reneged on its promise to respect Polish independence and subjugated it as a communist-led client state. Nationalist sentiment nevertheless remained strong and Poland went on to lead the Eastern Bloc in revolt against Russian overlordship. Starting in 1980, the country’s Solidarity trade union, led by later president Lech Wałęsa, pressured the Soviet-backed leadership for political freedoms, culminating in semi-free elections in 1989 that paved the way for a transition away from one-party rule across Central and Eastern Europe.

Poland has since oriented itself westward, joining the American-led NATO alliance in 1999 and entering the European Union in 2004. This shift has largely solved Poland’s geopolitical problem. Germany is no longer a territorial threat. Like the United States, it should now come to Poland’s defense in the event of another threat from the east.

But Poland has also relied on faraway powers before who failed to protect it. As Russia flexes its military muscle in Eastern Europe, Poland — unlike some of its Western allies — will not let its guard down. The country knows it cannot take its freedom for granted.