There is some pageantry and show inside McCormick Place. But the world leaders are talking serious business - with the war in Afghanistan front and center.
"I want to thank President Karzai for his cooperation and his delegation's hard work," President Obama said at a Sunday evening press event with the Afghan president.
Before the NATO summit officially got underway Sunday afternoon, the president had an hour long meeting with afghan President Hamid Karzai.
Both leaders agreed that NATO troops will be out of Afghan by the end of 2014. The Afghan president expressed his thanks to U.S. taxpayers for their support.
"Mr. President, I am bringing to you and to the people of the United States," Karzai said, "the gratitude of the Afghan people, for the support that your taxpayers' money has provided to the people of Afghanistan over the past decade."
Later, President Obama and NATO Secretary General Anders Rasmussen welcomed NATO leaders to McCormick Place, and then they got down to business.
The meeting opened with a tribute to NATO men and women who have been killed or injured in combat. Then the Secretary General thanked Chicago for its hospitality.
"Like NATO, Chicago draws together many cultures," Rasmussen said. "It's diverse, dynamic, and determined."
"As Anders mentioned, so many people here in Chicago trace their roots back to NATO countries," Obama said. "It is especially fitting that Chicago is the first American city outside of Washington D.C. ever to host a NATO summit."
At Sunday's session, the U.S. looked for NATO's help monitoring the violence inside Syria and for progress on a NATO policy toward Iran nuclear potential. Monday's sessions will focus on Afghanistan.
Behind the scenes, on all these issues, the U.S. is doing some arm twisting, to get NATO members to cover more of the costs - even in hard times.
The president then welcomed NATO leaders to an afternoon session where agreements were reached regarding missile defense shields, NATO's assistance with unmanned drones, and the policing of airspace over the Balkans.
"Our nations are stronger and more prosperous when we stand together," Obama said, "in good times and in bad."
"Our police department is doing a fabulous job of preserving the right of free speech and public safety," Mayor Emanuel said Sunday.
He didn't have a seat at the big round table. But the mayor was at McCormick Place Sunday afternoon, walking unnoticed among hundreds of international reporters, about an hour before the scrum between the protesters and police on Cermak.
When asked if he was pleased with the city's handling of the protests and NATO summit so far, Emanuel said the goal was for President Obama to showcase his hometown. The objective was to bring the world to Chicago, and Chicago to the world – and the mayor said it's working.
During a working dinner at Soldier Field Sunday night, the leaders of NATO's 28 member countries posed for a so called "family photo," and it's a pretty tight family.
The president of Pakistan was reduced to meeting only with secretary of state Hillary Clinton, not President Obama, because Obama is disappointed with Pakistan's progress in re-opening NATO supply lines.
The NATO alliance that has fought for a decade in Afghanistan is helping that nation shift toward stability and peace, but there will be "hard days ahead," President Barack Obama said Sunday as alliance leaders insisted the fighting coalition will remain effective despite France's plans to yank combat troops out early.
With a global economic crisis and waning public support for the war in the backdrop, world leaders opened a NATO summit confronted by questions about Afghanistan's post-conflict future: money for security forces, coming elections and more. They were also papering over the crack in the fighting alliance with the planned French withdrawal.
"We still have a lot of work to do and there will be great challenges ahead," Obama said. "The loss of life continues in Afghanistan and there will be hard days ahead."
Afghan forces will take the lead throughout the nation next year, instead of in 2014, despite uneven performance under U.S. and other outside tutelage so far. The shift is in large part a response to plummeting public support for the war in Europe and the United States, contributors of most of the 130,000 foreign troops now fighting the Taliban-led insurgency. A majority of Americans now say the war is unwinnable or not worth continuing.
Karzai said his nation is looking forward to the end of war, "so that Afghanistan is no longer a burden on the shoulder of our friends in the international community, on the shoulders of the United States and our other allies."
Obama said NATO partners would discuss "a vision for post-2014 in which we have ended our combat role, the Afghan war as we understand it is over, but our commitment to friendship and partnership to Afghanistan continues."
Newly elected French President Francois Hollande has said he will withdraw all French combat troops from Afghanistan by year's end -- a full two years before the timeline agreed to by nations in the U.S.-led NATO coalition.
"There will be no rush for the exits," NATO Secretary General Anders Fogh Rasmussen said. "Our goal, our strategy, our timetable remain unchanged."
Rasmussen denied there were fresh cracks in the alliance. He suggested a deal will emerge for France to move into a noncombat role but continue to support the international mission.
Before the one-hour meeting with Karzai, a senior U.S. official said Obama would focus on planning for Afghanistan's 2014 elections, as well as the prospect of a political settlement with the Taliban.
Karzai has said repeatedly he will step down from power when his term ends in 2014, opening the way for new elections. NATO's scheduled end of the war was built around those plans, with foreign forces staying until the 2014 election but exiting the country by 2015.
Obama and Karzai will discuss ways to ensure that political rivals can compete fairly in the run-up to the election, as well as ways to reduce fraud and support the winner who emerges, the official said.
Past Afghan elections were riddled with irregularities, and the U.S. applied heavy pressure to Karzai to schedule a second round of voting during the last presidential contest in 2009. The runoff was never held because Karzai's challenger pulled out, protesting what he said was an impossible level of corruption.
The election chapter opened a rift between the U.S. and Karzai, who suspected that the Obama administration wanted to replace him.
The Obama administration has mostly repaired its relationship with Karzai, but mistrust remains on both sides.
The U.S. official, speaking on condition of anonymity to discuss sensitive diplomacy, said before the meeting that Obama and Karzai also were to discuss prospects for a political settlement or peace pact between Karzai's government and the Taliban-led insurgency. The Taliban pulled out of U.S.-led talks in March, but separate talks among Afghan and other contacts continue, the U.S. official said.
The official said Obama believes political reconciliation is essential to the country's future security.
The Taliban is urging nations fighting in Afghanistan to follow France's lead and pull their international forces from the war this year.
"We call upon all the other NATO member countries to avoid working for the political interests of American officials and answer the call of your own people by immediately removing all your troops from Afghanistan," the group said in a statement before the meeting.
The insurgent group cited declining public support for the war in the West and said political leaders should listen to their constituents and get out of Afghanistan.
The national security-focused NATO summit caps an extraordinary weekend of international summitry. Obama and the leaders of the world's leading industrial nations convened at Camp David, the presidential retreat in Maryland, for two days of talks focused in large part on Europe's economic crisis.
Joining Obama and many of the G-8 leaders in Chicago are the heads of NATO alliance nations and other countries with a stake in the Afghan war.
Prominent among those nations is Pakistan. Tensions between the U.S. and Pakistan have been running high following several incidents, including the U.S. raid in Pakistan that led to the death of Osama bin Laden and a U.S. airstrike that killed two dozen Pakistani soldiers.
Both countries have been seeking to restore normal relations. Pakistani President Asif Ali Zardari's acceptance of an invitation to attend the NATO summit was seen as an indication that his country would reopen major roads used to supply NATO fighting forces in Afghanistan, a key U.S. demand.
White House officials said that while they believe an agreement on reopening the supply routes will be reached, they do not expect that to happen during the NATO meetings. The two nations are haggling over how much Pakistan will be paid to allow the heavy transport truck to pass through. A senior U.S. official said the two sides are far apart. The official spoke on condition of anonymity to discuss sensitive diplomacy.
Officials have indicated that Obama and Zardari will not hold a separate bilateral meeting until the matter is resolved. Although miffed, Zardari is expected to see Secretary of State Hillary Rodham Clinton and other U.S. officials in Chicago.
"I do hope that we will see a reopening of the transit routes in the very near future," Rasmussen said. "These negotiations will continue, but I am hopeful that they will be concluded in a positive manner."
The Associated Press contributed to this report.