The president invited a group of foreign policy experts and former government officials to dinner on Monday, and a separate group of columnists and magazine writers for a discussion on Wednesday afternoon. Although three New York Times columnists and an editorial writer were among those invited to the second session, this account is drawn from people unaffiliated with The Times, some of whom insisted on anonymity because they were not supposed to share details of the conversations.

The president they described was calm and confident, well versed on the complexities of the ISIS challenge and in no evident rush to end the discussions. A briefing book sat in front of him during the second of the sessions, but he never opened it. Vice President Joseph R. Biden Jr. and Secretary of State John Kerry joined him for the dinner, and Denis McDonough, the White House chief of staff, and Susan Rice, the national security adviser, sat in on the meeting with the journalists, but none of them said very much.

Mr. Obama was relaxed enough, as he discussed the array of foreign policy crises facing him, that at one point he ridiculed President Vladimir V. Putin’s rationale for intervening in Ukraine to protect Russian speakers by saying the United States should intervene in Mexico to protect enclaves of Americans. When a writer jokingly asked if he was announcing plans to invade Mexico, he laughed and said no, Canada, because it has more oil.

The guests came away with different impressions; some said they thought he still seemed ambivalent about the course he was taking in Iraq and Syria, while others said he appeared at peace.

“It’s fair to say when the president imagined where he’d be in this sixth year, I doubt he expected to be here,” said Richard N. Haass, president of the Council on Foreign Relations and a former Bush administration official who was among the guests at the dinner Monday. “But he’s been forced to react to events here.”

Jane Harman, a former Democratic congresswoman from California who now heads the Woodrow Wilson International Center for Scholars, said she thought Mr. Obama had evolved. “He was all in,” she said. “I don’t know what the definition of reluctant is, but I certainly think he’s totally focused, this man at this time.”

If his thinking has evolved, Mr. Obama admitted no errors along the way. While some critics, and even his former secretary of state, Hillary Rodham Clinton, have faulted him for not arming moderate Syrian rebels years ago, Mr. Obama does not accept the premise that doing so would have forestalled the rise of ISIS.