"Croatia's success was far from inevitable. In fact, it is a testament to the courage of its citizens and leaders who overcame the temptations of ultranationalism and resentment. Letting go of the past is a daily struggle. And, day by day, Croatians kept faith with an ambitious vision and built the democratic institutions that opened the doors to NATO and now the EU," Biden wrote.
"This achievement belongs to the Croatian people. But it also speaks to the transformative power of the European project guiding countries toward the rule of law, open markets, prosperity and peace."
Croatia is further along that journey than some may think, Biden wrote, adding that Croatia "has been a NATO ally since 2009 and a contributor to security around the world, including Afghanistan. Once other countries sent peacekeepers to Croatia; now Croatia contributes to peacekeeping missions in Kosovo, Haiti and the Western Sahara."
"Croatia's accession to the EU also raises the stakes for neighbours who face a risk of being left behind. Over time, the borders of the EU should unite the countries of southeastern Europe rather than divide them," Biden wrote.
"But first, Croatia's neighbours must make difficult choices that will pave their own paths into Europe. It is in the interest of the US, Croatia and the rest of Europe that they succeed. History has no greater monument to the idea that countries need not repeat the conflicts of the past than the EU – and no greater mechanism than integration to ensure they don't," he wrote, adding, "That is why Croatia is working to bring the very people it fought less than a generation ago into the European fold."
"Serbia and Kosovo have been locked in a deep and bitter struggle – until now. Through dialogue, co-operation and painful compromise, prime ministers Ivica Dacic and Hashim Thaci have reached a historic agreement to normalise relations. The next steps will not be easy, but these leaders have given their citizens an unprecedented opportunity to build a future defined by respect for rights, shared prosperity and peaceful coexistence."
"Montenegro and Albania, too, have hard work left to do, but they are making progress toward European integration, tackling economic and political reforms, fighting corruption and strengthening the rule of law," Biden wrote.
"Macedonia must stay the course of reform, address its interethnic tensions and, with Greece, summon the courage to find a mutually acceptable solution on its name," he wrote, adding that, unfortunately, little progress had been achieved in Bosnia and Herzegovina whose people "deserve better."
"No country can completely leave behind its history or forget its tragedies. And nor should they. But countries can choose to put their futures first and act for the well-being of generations to come. That is what Croatia has done. And the result is that dreams that seemed inconceivable 20 years ago today are wonderfully, irreversibly real," Biden wrote.
"That is both a cause for celebration and a reminder of what is possible. We congratulate Croatia and recommit ourselves to the larger goal of welcoming the entire Balkans into a Europe that is whole, free and at peace," he said in his piece for the Financial Time.