The bill of particulars against Mr. Obama is long. In the view of his critics, he failed to stanch the rise of the Islamic State in Iraq and Syria when he rejected proposals to arm more moderate elements of the Syrian resistance. He left a vacuum in Iraq by not doing more to leave a residual force behind when American troops exited in 2011. And he signaled weakness to President Vladimir V. Putin of Russia, encouraging the Kremlin to think it could intervene in Ukraine without fear of significant consequence.

“I certainly do not think President Obama is responsible for all of the world crises that have taken place during his time in office,” said William C. Inboden, a former national security aide to President George W. Bush and executive director of the William P. Clements Jr. Center on History, Strategy and Statecraft at the University of Texas. “But he is responsible for actions and attitudes he took that have contributed to some of those crises — and he is also responsible for how he responds, or fails to respond.”…

Former Representative Lee H. Hamilton, Democrat of Indiana, said presidents can influence but not dictate events. “Americans have a very strong tendency to think that whatever we do is the most important thing happening everywhere, and we have so much power and so much clout that we can control events everywhere,” said Mr. Hamilton, now director of the Center on Congress at Indiana University. “That’s part of what he’s wrestling with here.”

As it happens, Mr. Obama’s policy of restraint seems to match the public mood — polls find little appetite for robust American intervention in Ukraine, Syria or Iraq. And yet, there is a palpable sense of disappointment with Mr. Obama’s leadership on the world stage as well. Fifty-eight percent of Americans in a recent New York Times/CBS News poll disapproved of his handling of foreign policy, the highest of his presidency.