WASHINGTON >> President Barack Obama chooses his words with particular care when he addresses the volatile connections between religion and terrorism. He and his aides have avoided labeling acts of brutal violence by al-Qaida, the so-called Islamic State and their allies as “Muslim” terrorism or describing their ideology as “Islamic” or “jihadist.”

With remarkable consistency — including at a high-profile White House meeting this week, “Countering Violent Extremism” — they have favored bland, generic terms over anything that explicitly connects attacks or plots to Islam.

Obama aides say there is a strategic logic to his vocabulary: Labeling noxious beliefs and mass murder as “Islamic” would play into the hands of terrorists who claim that the United States is at war with Islam itself. The last thing the president should do, they say, is imply that the United States lumps the world’s 1.5 billion Muslims with vicious terrorist groups.

But Obama’s verbal tactics have become a target for a growing chorus of critics who believe the evasive language is a sign that he is failing to look squarely at the threat from militant Islam. The vague phrasing, they say, projects uncertainty and weakness at a time when extremists claiming to fight for Islam threaten America and its interests around the world.

“Part of this is a semantic battle, but it’s a semantic battle that goes to deeper issues,” said Peter Wehner, a veteran of the past three Republican administrations and a senior fellow at the Ethics and Public Policy Center. “Self-deception is not a good idea in politics or international affairs. We’re lying to ourselves, and the world knows it.”

While the most vehement criticism has come from Obama’s political opponents on the right, a few liberals and former security officials have begun to echo the criticism.

“You cannot defeat an enemy that you do not admit exists,” Michael T. Flynn, a retired Army lieutenant general and director of the Defense Intelligence Agency from 2012 to 2014, told a House hearing last week. “I really, really strongly believe that the American public needs and wants moral, intellectual and really strategic clarity and courage on this threat.”

Akbar Ahmed, chairman of Islamic studies at American University and author of a book on Islam in America, said he supported the Obama administration’s care in avoiding a counterproductive smear of all Muslims. But he said the president sometimes seemed to bring an academic approach to a visceral, highly politicized discussion.

“Obama’s reaching a point where he may have to ditch this almost scholastic position,” Ahmed said. “He sounds like a distinguished professor in the ivory tower, and he may have to come down into the hurly-burly of politics.”

Addressing the extremism conference Wednesday, Obama acknowledged the complaints and took pains to try to explain his approach.

“Leading up to this summit, there’s been a fair amount of debate in the press and among pundits about the words we use to describe and frame this challenge, so I want to be very clear about how I see it,” the president said. “Al-Qaida and ISIL and groups like it are desperate for legitimacy. They try to portray themselves as religious leaders, holy warriors in defense of Islam.”

But Obama said that “we must never accept the premise that they put forward, because it is a lie.” The operatives of al-Qaida and the Islamic State, also known as ISIS or ISIL, “are not religious leaders — they’re terrorists,” he said.

The president’s comments suggest that the criticism has disturbed him. “You know your talking points are no longer working when you have to talk about your talking points,” said Peter D. Feaver, a political scientist at Duke who was deeply involved in shaping President George W. Bush’s language while he worked at the White House from 2005 to 2007.

Choosing what to say about the enemy during the long campaign against al-Qaida, and now the Islamic State, was a challenge for Bush as well as for Obama, Feaver said. The nation’s terrorist enemies define themselves as fighters for Islam, lace their propaganda with quotes from the Quran and claim to speak for all Muslims. But an overwhelming majority of Muslims worldwide reject the al-Qaida ideology and condemn terrorist attacks.

Bush, too, struggled at times to find the right terms for the fight against al-Qaida. He used and then quickly dropped the word “crusade” for the U.S. campaign against terrorism, concerned that he was playing into the terrorists’ view of a centuries-long clash of civilizations.

He favored the formula “war on terror” but was battered by critics inside and outside the government who said that it was impossible to wage war against a tactic, Feaver recalled. For months before a major speech by the president in 2005, different agencies fought over what, exactly, Bush should call the enemy.

In the end, he effectively threw up his hands. “Some call this evil Islamic radicalism,” he said in the speech. “Others, militant jihadism. Still, others Islamo-fascism. Whatever it’s called, this ideology is very different from the religion of Islam.” But he went on to regularly use the term “Islamic radicalism,” which Obama has shunned.

Many advocates for Muslims appreciate Obama’s care in keep their religion separate from the terrorist groups whose claims they reject. “We support the Obama administration and the administration before them for not falling into the al-Qaida-ISIS trap of saying this is a religious war,” said Farhana Khera, executive director of Muslim Advocates, a national group.

But even Khera complained that the name of the White House conference on the topic was too vague. While the label was “violent extremism,” the vast majority of speakers spoke only about Islamic extremism, ignoring all other kinds, she said. “If the summit were called ’Countering ISIS,’ that would be fine,” she said. “But it’s not.”

Daniel Benjamin, who served as the State Department’s top counterterrorism official from 2009 to 2012, said he believed the dispute was a “pseudocontroversy” driven largely by domestic politics, even if it has produced some clumsy moments in the White House press room. What the debate has missed, he said, is that any U.S. president has to think about how his words are received overseas.

“Our allies against ISIS in the region are out there every day saying, ‘This is not Islam,’” said Benjamin, now at Dartmouth. “We don’t want to undermine them. Any good it would do to trumpet ‘Islamic radicalism’ would be overwhelmed by the damage it would do to those relationships.”

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