In only his third address to the nation from the Oval Office, President Barack Obama reassured Americans on Sunday night that the United States is equipped to meet the dangerous and "evolving" threat of terrorism.
As U.S. and other Western responses have gained ground against organized, wide-scale terrorist attacks, "growing efforts by terrorists to poison the minds" of home-grown attackers are evolving, the president said.
"As a father to two young daughters who are the most precious part of my life, I know that we see ourselves with friends and co-workers at a holiday party like the one in San Bernardino. I know we see our kids in the faces of the young people killed in Paris," Obama said.
"And I know that after so much war, many Americans are asking whether we are confronted by a cancer that has no immediate cure," he said, before answering: "The threat from terrorism is real, but we will overcome it."
The president offered no new details on the investigation into the San Bernardino attack, saying that "so far, we have no evidence that the killers were directed by a terrorist organization overseas or that they were part of a broader conspiracy here at home."
Instead, Obama compared the mass killing to attacks in Chattanooga, Tennessee; Fort Hood, Texas; and Boston, where, he said, "terrorists turned to less complicated acts of violence" and where the Internet erased "the distance between countries."
Outlining the U.S. strategy against ISIS, which Obama described as a "cult of death" that "does not speak for Islam," the president cautioned against a "costly ground war," which he said would serve only as a recruitment tool.
"That's what groups like [ISIS] want," he said.
Obama said the United States and its allies would continue disrupting plots, targeting terrorist infrastructure and finances, and providing training and equipment to Iraqi and Syrian fighters. He said he would also pursue a cease-fire agreement in Syria, which would allow for a "common goal" between the United States and Russia to pursue ISIS.
At home, Obama said, the State and Homeland Security departments will review the visa program that allowed Tashfeen Malik — who with her husband carried out the San Bernardino attack — into the country to determine whether stronger screening is needed.
Obama also made a pitch for gun control, saying it "should be more difficult" to buy high-powered assault-style rifles — like those used in last week's attack — and that people on no-fly lists shouldn't be allowed to buy guns.
"What could possibly be the argument for allowing a terrorist suspect to buy a semi-automatic weapon?" he said. "This is a matter of national security."
Obama's remarks came amid an acrimonious political campaign that has seen Republican presidential contenders blast him over his handling of groups like ISIS.
On NBC's "Meet the Press" on Sunday, Lindsey Graham said the president had been "overwhelmed by radical Islam," while Donald Trump suggested to the Republican Jewish Coalition Presidential Candidates Forum in Washington last week that "there was something going on" with Obama because he refused to use the term "radical Islamic terrorism," according to The Hill newspaper.
Obama's address appeared to do little to persuade his Republican critics. On Twitter, Trump grumbled that the president still "refused to say (he just can't say it), that we are at WAR with RADICAL ISLAMIC TERRORISTS."
In a statement, Republican National Committee Chairman Reince Priebus was a little more measured, saying:
"The path laid out by President Obama and supported by Hillary Clinton has not worked, and ISIS has only gained in strength. The attacks in San Bernardino should serve as a wake-up call for Obama and Clinton that the way to victory is not through the status quo but refocusing our efforts to defeat ISIS."
Obama has rarely used the Oval Office — the most symbolic representation of his authority — to speak to the nation. He announced the end of U.S. combat operations in Iraq from there in August 2010, and two months before that, he laid out his plans to secure American energy after the BP oil spill in the Gulf of Mexico.
A senior administration official said that after the Paris terrorist attacks last month, followed by numerous thwarted ISIS plots and then the San Bernardino shootings, Obama decided he needed to address "the significant concerns and very real and legitimate fears in the United States and around the world."
The choice of the Oval Office for Sunday night's address reflected "the seriousness with which we are taking the issue," the official said. At the same time, the address was meant to "step back and provide context for people," not to announce new policies or strategies, the official said.
Obama referred to history in reinforcing the message Sunday night:
"Let's not forget that freedom is more powerful than fear, that we have always met challenges — whether war or depression, natural disasters or terrorist attacks — by coming together around our common ideals as one nation, as one people," he said. "So long as we stay true to that tradition, I have no doubt America will prevail."
Cris Jansing and Andrea Mitchell contributed reporting to this article. It originally appeared on NBC News.com