BERLIN -- Summoning the harsh history of this once-divided city, President Barack Obama on Wednesday cautioned the United States and Europe against "complacency" brought on by peace, pledging to cut U.S. deployed nuclear weapons by one-third if Cold War foe Russia does the same.
The president also declared that his far-reaching surveillance programs had saved lives on both sides of the Atlantic, as he sought to defend the controversial data-mining to skeptical Europeans.
Speaking against the soaring backdrop of the Brandenburg Gate, Mr. Obama said "bold reductions" to the U.S. and Russian nuclear forces were needed to move the two powers away from the war posture that continues to seed mistrust between their governments.
"We may not live in fear of nuclear annihilation, but as long as nuclear weapons exist, we are not truly safe," he said as he closed a three-day visit to Europe, his first trip to the continent since winning re-election.
Privacy-protective Germany was particularly eager for answers about the sweeping programs run by the National Security Agency. Chancellor Angela Merkel used a news conference Wednesday with Mr. Obama to appeal for "due diligence" in evaluating the privacy concerns, although she avoided a direct public confrontation with the president.
Mr. Obama offered a lengthy defense of the court-approved surveillance of Internet and phone records, describing it as a targeted effort that has "saved lives."
The centerpiece of the president's visit was the afternoon speech at the Brandenburg Gate, where the Berlin Wall once stood, marking divisions between East and West Germany.
Mr. Obama's address drew inevitable comparisons to John F. Kennedy's famous "Ich bin ein Berliner" (I am a Berliner) speech exactly 50 years ago, as well as Mr. Obama's own thunderous welcome when he arrived in the city as a presidential candidate in 2008. More than 200,000 people filled the streets near Berlin's Victory Column for that address, a reflection of Europe's high hopes for the rising American political figure.
Now in his fifth year as president, Mr. Obama remains popular in Europe. But the crowd that gathered to hear him speak Wednesday was far smaller and less exuberant than it was in 2008 -- just 4,500 people wilting in the sun on an unseasonably warm June day.
The wide-ranging address enumerated a litany of challenges facing the world, punctured by Mr. Obama's calls for the West to reignite the spirit that Berlin displayed as many citizens struggled to reunite the city during the Cold War. "Today's threats are not as stark as they were half a century ago, but the struggle for freedom and security and human dignity, that struggle goes on," he said. "And I come here to this city of hope because the test of our time demands the same fighting spirit that defined Berlin a half-century ago."
Mr. Obama's nuclear pledges signaled a White House effort to revive a national security matter that has languished in recent years. But he set no deadlines for reaching a negotiated agreement with the Russians, and his proposals were quickly questioned by officials in Moscow.
Russian foreign affairs official Alexei Pushkov told the Interfax news agency that the proposals needed "serious revision so that they can be seen by the Russian side as serious and not as propaganda proposals." Yuri Ushakov, foreign policy aide to President Vladimir Putin, told reporters that Moscow had already told the White House that any further arms reduction would have to involve countries besides just Russia and the United States.
Mr. Obama also faced questions during his news conference with Ms. Merkel on deepening U.S. involvement in Syria and potential pitfalls in efforts to peacefully wind down the U.S.-led war in Afghanistan.
On Syria, Mr. Obama pointedly refused to detail steps his government has recently taken to arm rebels seeking to overthrow Syrian President Bashar Assad. U.S. officials have confirmed that the administration has approved weapons and ammunition shipments to the opposition.