Transcript for President Obama, Re-Assurer in Chief, Stops in Germany, Greece
And finally tonight we're on the road with Barack Obama who is trying to reassure nervous Europeans about his successor. My "Nightline" co-anchor is traveling with the president. This was to have been his victory lap, a final jaunt across Europe. Instead to many president Obama's trip has felt like a low key and equally lonely apology tour. America's reassurer in chief to the world. I think the president-elect is going to see fairly quickly that the demands and responsibilities of a U.S. President are not ones that you can treat casually. The president and his staunchest European ally, German chancellor Angela Merkel fielding as many questions about the future leader not in the world, Donald J. Trump. I am encouraged by the president-elect's insistence that nato is a commitment that does not change. There seems to be great affection for president Obama here in Berlin. The gentleman president as one German put it. As for the man who he be our 45th president, not so much. What do you think of our president-elect Donald Trump? No comment. He's a little crazy. It will be exciting. Exciting. Why? I guess. He's a businessman. The president's first stop will be here in Athens, Greece, the birthplace of democracy. A private tour of the acropolis. The tourist in chief equally popular here. Much of Greece and parts of Europe share the same sense of economic despair as a large number of Americans who voted for trump. Unemployment here 24%. Our cabbie told us today he works 14 to 17 hours daily, seven days a week just to make ends meet. It's difficult. Then there's the crushing toll of a refugee crisis. Waves pouring into Europe from the war ravaged Middle East. There's more than a few Greeks sympathetic to trump's call for stronger borders in the U.S. So it is with that backdrop abroad and tensions back home that president Obama passes through Europe a final time as leader of the free world. Remember his first trip to Germany as candidate Obama? Not a single gray hair. 200ses this Germans enraptored by his every word. But eight years later the audacity of hope gives way to the uncertainty of now. Yet optimism is still a valued currency, home and abroad. Let's hope the best. For "Nightline" I'm Byron pi
This transcript has been automatically generated and may not be 100% accurate.