04/16/2014 04:00 pm ET Updated Jun 16, 2014

The European Union's 16th Century Predecessor

A few days ago, my friend Congressman Mario Diaz-Balart from Florida asked me which cities I would recommend he sees if he gets a chance to visit Poland. He was somewhat surprised that I didn't begin the list with Warsaw or Krakow, which are usually must-see destinations for any visitor to Poland. My answer was Lublin. Just over a 100 miles from Warsaw, this city is not only the home of countless museums, galleries, pearls of architecture and an amazing Old Town, it is the European Union's window to the east and one of the last cities on its frontier.

An hour drive to Ukraine, Lublin is both the EU's bridge and fortress of democracy during these times of political uncertainty and conflict. The historical significance of this city -- located on the crossroads of Western and Eastern civilizations, where for centuries Catholic, Orthodox and Jewish peoples lived side by side -- provides lessons on the challenges standing before the Free World. Four centuries before the European Union, there was a republican endeavor that created a sphere of stability and prosperity from the Baltic to the Black Sea. It was called the Lublin Union.

At the same time that Ivan the Terrible was consolidating absolute power in Russia and his Oprichniks were slaughtering the tsar's enemies by the thousands, the Lublin Union of 1569 established a Commonwealth of the Polish and Lithuanian nobility, whereby its representatives would have the power to elect the state's monarch and sit together in one parliament. Despite its shortcomings, the Lublin Union created an empire of ideals and toleration far ahead of its time. In terms of territory, it transferred the lands of modern-day Ukraine from the Grand Duchy of Lithuania to the Polish Kingdom. As a result, Poles and Jews migrated east in vast numbers to the territories of what is now Ukraine, including Kyiv.

Although the Lublin Union allowed Poland and Lithuania to maintain separate armies, they agreed to have a united foreign and defense policy. Moreover, the signatories retained their separate languages, but introduced a single currency. Sound familiar? Although centuries apart, other similarities between the Lublin Union and the European Union are striking. Its member states kept separate central administrations but adopted a unified legal code and lifted trade barriers. This was a 16th century version of the EU's Single Market.

The greatest drawback of the Lublin Union, which created the state formally known as the Commonwealth of Two Nations, was that it was the union of two nations -- not three. The shortsightedness of the Polish and Lithuanian nobility hampered the Ukrainian Cossacks from becoming full-fledged partners in this new regional superpower. This was the Lublin Union's undoing and, ultimately, proved a decisive factor in Poland's demise and loss of independence beginning with its first partition in 1772. Centuries ago, like today, Ukraine was the missing link.

Russia's recent annexation of the Crimea, its ongoing policy of destabilizing Ukraine's eastern regions by actively supporting separatists, and the Kremlin's energy blackmail, reiterate that without Ukraine Europe will never be truly "whole and free." That is why we cannot repeat the mistakes of the past. When roaming Lublin's cobblestone streets past the 14th century Krakowska Gate or the Neo-Gothic Trinitarian Tower, the city stirs thoughts of both triumphs and unfulfilled glory. But first and foremost, it is a city of hope. As the home of six universities and over 3,000 foreign students (with close to 300 students from the U.S.), Lublin is the city where the past meets the future. It is the city that shapes tomorrow's leaders. Over 1,500 students in Lublin are from Ukraine. One day, they will be the statesmen and stateswomen that a democratic and prosperous Ukraine needs. That is why the European Union should not repeat the mistakes of its 16th century predecessor; that is why there needs to be a place for a free Ukraine in a united Europe.