BERLIN (AP) - Summoning the harsh history of this once-divided city, President Barack Obama on Wednesday cautioned the U.S. and Europe against "complacency" brought on by peace, pledging to cut America'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, Obama said that "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," Obama said as he closed a three-day visit to Europe, his first trip to the continent since winning re-election.
Obama is grappling with both domestic disputes and foreign policy challenges that have distracted from his second term agenda. Two matters - the fierce civil war in Syria and the U.S. government's domestic surveillance program - trailed Obama in Germany, as well as during the Group of 8 summit in Northern Ireland earlier this week.
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 with Obama Wednesday to appeal for "due diligence" in evaluating the privacy concerns, though she avoided a direct public confrontation with the president.
"There needs to be proportionality," she said of the U.S. programs. "This is going to be an ongoing battle."
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."
"We know of at least 50 threats that have been averted because of this information, not just in the United States but in some cases threats here in Germany," he said.
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. Obama, standing behind a pane of bulletproof glass, spoke from the gate's East front, a location that would have been inaccessible to an American president in an earlier era.
The wide-ranging address enumerated a litany of challenges facing the world, punctured by 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."
Obama's nuclear pledges signaled an effort by the White House 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 the proposals needed "serious revision so that they can be seen by the Russian side as serious and not as propaganda proposals."