“At least since World War II, presidents have been unwilling to discuss deficiencies in capability because they’re expected to do everything, and they like that sense of omnipotence,” said Jeremy Shapiro, a former Obama State Department official now at the Brookings Institution. “Obama has been trying to change that in the last year because he senses that the requirements of omnipotence have gotten so far out of whack with what he can actually accomplish that he needs to change the expectations.”

The risk, naturally, is that the president looks as if he is simply trying to excuse his own actions, or inactions, as the case may be.

“It’s become a refrain to the point where I think people are becoming quite critical that that’s his response to everything,” said Daniel L. Byman, a former member of the Sept. 11 commission staff now teaching at Georgetown University. “He’s not differentiating between things he can influence and those that he can’t.”

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.”