President-elect Donald Trump's campaign pledge to wage war on "radical Islamic terrorism" is about to become U.S. policy.
In its emphasis on ideology, it is a war that puts him at odds with his two immediate predecessors. While both former President George W. Bush and President Barack Obama have avoided casting the war on terror in ideological terms for fear of alienating Muslim allies, Trump has stressed that very dimension and the need to counter it ideologically.
"Containing the spread of radical Islam must be a major foreign policy goal of the United States," Trump said in April in the first of two major foreign policy speeches he delivered during the campaign. "Events may require the use of military force. But it's also a philosophical struggle, like our long struggle in the Cold War."
More than campaign rhetoric, it seems to be a deeply held view. In the weeks since his Nov. 8 election, Trump has steadfastly stuck to his hardline position on terror even as he's softened his views on other hot-button issues.
After a Tunisian man drove a truck through a crowded Christmas market in Berlin last month, killing 12 people, Trump tweeted: "This is a purely religious threat, which turned into reality. Such hatred! When will the U.S., and all countries, fight back?"
And when he was asked about his controversial campaign call to bar Muslims from entering the country, he replied: "You know my plans all along — I've been proven to be right."
Blaise Misztal, director of the national security program at the Bipartisan Policy Center in Washington, said Trump sees radical Islam as an ideological threat to his nationalistic vision of "making America great again."
"I think by seeing the threat as an ideological one, President Trump will see the problem as not just stopping attacks but stopping the spread of that ideology and stopping the potential for further radicalization," Misztal said.
Trump wasn't always so hawkish on fighting terror. Nor was he the first to warn about radical Islam.
The credit for popularizing the phrase goes to his Republican rivals — and some of his subsequent advisers, such as incoming chief strategist Stephen Bannon — who repeatedly chastised Obama for refusing to utter the words. Indeed, in his June 2015 presidential announcement, Trump made no mention of radical Islam and called China a "bigger problem" than Islamic State.
But Trump's rhetoric grew increasingly bellicose as the campaign wore on and a rash of terrorist attacks in Europe and the United States unnerved voters, leading him to make some of his campaign's most incendiary comments and proposals.
After a terror attack in Paris in November 2015 and a deadly shooting by a Muslim couple in San Bernardino, California, the following month, Trump proposed a temporary ban on Muslims entering the U.S.
In March 2015, he told CNN that "Islam hates us" and later defended his comment, saying "large portions of Muslims" have "tremendous hatred" for the West. And two months later when a Muslim-American gunman killed 49 people at a gay nightclub in Orlando, Trump blamed the violence on radical Islam and said he favored a suspension of immigration from countries with "a proven history of terrorism."
In August, with Americans still jittery over terrorism, Trump delivered what some experts saw as his most coherent policy statement on national security. Comparing radical Islam to fascism and communism, he championed a "new approach" and a "long-term plan" to fight what he branded an "ideology of death."
"All actions should be oriented around this goal, and any country which shares this goal will be our ally," he told supporters at Youngstown University in Ohio, echoing Bush's post-9/11 rhetoric.
He advocated "ideological warfare" against Islamic State and vowed to work with NATO and "our friends in the Middle East" and to find "common ground" with Russia to defeat the group.
"My administration will aggressively pursue joint and coalition military operations to crush and destroy ISIS, international cooperation to cut off their funding, expanded intelligence sharing, and cyberwarfare to disrupt and disable their propaganda and recruiting," he said. ISIS is an acronym for Islamic State.
Trump said the common thread among terrorist attacks since 9/11 was the involvement of immigrants or the children of immigrants, and he called for an ideological test for immigrants to screen out those who do not "share our values and respect our people.”
The policy implications of Trump's call to arms remain to be seen. Colin Clarke, a political scientist at RAND, said it is too early to tell how the rhetoric of Trump and his advisers translates into policy.
"That still doesn't tell you what he'll do differently in terms of combating the threat," Clarke said. "It doesn't tell you how he's going to allocate resources any differently than the Obama administration."
Critics of Obama's refusal to acknowledge a link between terrorism and Islam hailed Trump's drive to highlight the issue, but they cautioned against painting the world's 1.5 billion Muslims with a broad ideological brush.
"Actually it does have something to do with Islam," said former CIA Director Michael Hayden. "A lot of it is about Islam. But I quickly add, it's not all about Islam, and for God's sake, it's not about all Muslims."
Apart from his controversial Muslim ban and proposal to work with Russia, nearly everything Trump has proposed to fight terror — bombing IS, working with Middle Eastern allies, and using drones and special forces — are policies that have been carried out by the Obama administration.
"I haven't seen anything [new]," Clarke said. "I've been looking. Trust me. I think a lot of people have."
In securing the American homeland against terrorist attacks since 9/11, the U.S. may have exhausted nearly all the law enforcement, investigative and intelligence tools at its disposal, Hayden said. While mass-casualty attacks like 9/11 have grown highly improbable, he warned that so-called lone wolf attacks by homegrown extremists will be hard to prevent.
According to Pentagon data, in the two years since the U.S. launched a bombing campaign to roll back IS, coalition aircraft have carried out nearly 17,000 airstrikes in Iraq and Syria, damaging or destroying nearly 32,000 targets.
"Getting tough" has its limits, Hayden cautioned. "I'm fond of saying, if being tough is all you needed, if you could kill your way out of this, we'd have been done a decade ago," Hayden said.
But Trump advisers say the threat of international terrorism has grown over the last eight years and requires a new strategy.
"I do think there are, there are clear and broad distinctions between the past administration and the future administration," said James Carafano, director of foreign policy studies at the conservative Heritage Foundation who advises the Trump transition team on foreign policy. "And it's logical that there ought to be big changes because by almost every observable measure, the problem of transnational terrorism is worse than it was eight years ago."