Given Iraq’s military shortcomings, especially in air power, intelligence coordination and logistics, American and Iraqi officials had long expected that some American military presence, even if only in an advisory role, would continue beyond 2011. That is the deadline for a troop withdrawal negotiated under President George W. Bush more than three years ago and adhered to, so far, by President Obama.

Even as contingency planning for any lasting American mission has quietly continued in Baghdad and at the Pentagon, however, the shifting political landscape in both countries has made it increasingly possible that the 2011 withdrawal could truly be total, the officials said. Both Prime Minister Nuri Kamal al-Maliki of Iraq and Mr. Obama, struggling to retain the support of their political bases, have repeated their public vows to adhere to the deadline…

The question is so politically delicate — here and in Washington — that officials would speak only on condition of anonymity. Further, they say the topic has not been broached in detail even in recent private meetings between senior Iraqi and American officials, including one in Baghdad last week between Mr. Maliki and the chairman of the Joint Chiefs of Staff, Adm. Mike Mullen.

“Maliki can’t start asking right now for a large, extended American footprint,” a senior administration official said. “First of all, there is no Maliki government. And second, it would introduce a hugely controversial issue just when he doesn’t need it.”