Do you think they will solve the problem in this one meeting? Fingers crossed, because we have ISIS getting closer and closer to nuclear bombs.
Leaders from more than 50 countries gathered here on Thursday at the behest of President Obama to try to reduce the threat from nuclear weapons. But the Nuclear Security Summit, the fourth and possibly last of these gatherings, opened with a palpably subdued atmosphere.
President Vladimir V. Putin of Russia is boycotting the meeting, which makes major breakthroughs on global security unlikely, given his country’s vast nuclear stockpile. And with Mr. Obama — who conceived and championed these meetings — leaving office next year, several experts said it was unlikely that a Nuclear Security Summit would even happen again.
Mr. Obama is expected to celebrate some achievements, including Japan’s commitment to move out 500 kilograms of highly enriched uranium and plutonium, which it is transferring to the United States. But analysts said major security risks remained, not least the large stockpiles of weapons-grade nuclear fuel held in military facilities around the world.
Binding global agreements on nuclear security remain elusive, so the meeting is likely to focus on regional threats. The terrorist attack in Belgium last week has cast a shadow over the gathering, particularly after reports that fighters for the Islamic State were seeking to penetrate a nuclear facility to obtain material for a so-called radioactive dirty bomb.
Mr. Obama has added a session to discuss the status of the military campaign against the Islamic State, in which the administration continues to claim gains. In the afternoon, he will meet with President François Hollande of France; the Islamic State killed more than 125 people in Paris last November. It is Mr. Obama’s only planned one-on-one meeting with a leader, aside from President Xi Jinping of China.
The president’s refusal to meet individually with President Recep Tayyip Erdogan of Turkey has roiled the diplomatic waters, though the White House on Wednesday did not rule out the possibility that the two men might meet briefly on the margins of the summit.
Mr. Putin’s snub was not unexpected, given the rift between Russia and the United States over Moscow’s military aggression in Syria and Ukraine. But the White House pointed out that Russia has nevertheless cooperated on nuclear issues, not least its role in the multi-party talks with Iran over curbing its nuclear program. (Iran was not invited to attend the summit.)