"Here we see the strength of free nations that stand united," Obama told thousands of people gathered in Warsaw to celebrate the anniversary of elections that led to the end of communist rule 25 years ago.
"This land was invaded and conquered, carved up and occupied," he said. "But those days are over. Poland understands as few other nations do that every nation must be free to chart its own course, to forge its own partnerships, to choose its own allies."
Obama declared Ukrainians the "heirs of Solidarity" — a tribute to the movement that led the push for Poland's political transformation. Like the Poles, the Ukrainians are fighting for self-determination, he said.
"Beaten and bloodied, they refused to yield," he said of the Ukrainians. "Threatened and harassed, they lined up to vote. They elected a new president in a free election — because a leader's legitimacy can only come from the consent of the people."
Obama's remarks came shortly after his first formal meeting with Ukrainian President-elect
Ukrainian officials have been open about their requests for more
But such aid would probably be tied to long-term reforms in a country that has been plagued by corruption and weak institutions. Poroshenko and Obama discussed plans for such reforms, as well as easing Ukraine's dependence on Russian energy and efforts to decentralize its federal control to accommodate calls for more autonomy in the east.
The White House believes those plans provide "a basis for the reduction of tensions," yet Obama put the onus on Russia to shift the course of the conflict. Western officials accuse Moscow of backing separatist groups and are calling on the Kremlin to use its sway with the militias to end the fighting.
"The days of empire and spheres of influence are over," Obama said, standing behind protective glass at the ceremony in Castle Square, where Solidarity protesters once gathered. "Bigger nations must not be allowed to bully the small, or impose their will at the barrel of a gun or with masked men taking over buildings."
The speech was Obama's second recent attempt to frame the conflict in Ukraine in terms of history and of his own foreign policy agenda. In March, the president warned against casting the dispute as a return to Cold War. On Wednesday, he seemed more comfortable embracing some of the hard-line rhetoric of the era.
"Our free nations will stand united so that further Russian provocations will only mean more isolation and costs for Russia," he said. "Because after investing so much blood and treasure to bring Europe together, how can we allow the dark tactics of the 20th century to define this new century?"
"As allies, we have a solemn duty — a binding treaty obligation — to defend your territorial integrity," Obama said. "And we will."
One analyst compared the address to the rhetoric of Obama's predecessor, whose foreign policy approach Obama has repeatedly denounced.
"This was a strong and powerful speech about the vital importance for countries to be able to choose their political, economic and security future and not have other, larger nations dictate their future to them," said Heather Conley, director of the Europe program at the Washington-based Center for Strategic and International Studies.
"As much as the Obama administration has shied away from anything that smacks of President Bush's 'freedom agenda,' this speech was as close to an Obama 'freedom of choice' agenda that I have read," she said.
Still, while Obama's speech included soaring promises, he has no clear way to fulfill many of them.
He declared that he would not accept Russia's
After the remarks, Obama flew to Brussels for a meeting with the Group of 7 economic powers to discuss next steps on Ukraine. The group has sought to isolate Russian President
Several Western leaders plan to meet with Putin later in the week in France as they gather to celebrate the 70th anniversary of the Allied landing at Normandy. Meanwhile, the push to impose additional sanctions on Russian businesses appears to have lost some steam amid resistance from key sectors.