President Obama addressed the attacks in San Bernardino, Calif., and overseas from the Oval Office. (Associated Press)

In addressing the nation Sunday evening, President Obama turned to a venue he doesn’t like to discuss a subject he would rather avoid.

His decision to speak on the terrorist threat from the Oval Office, just days after the deadly attack in San Bernardino, Calif., reflects a broad concern in the White House that the American people, distracted by the overheated cacophony of the campaign season, are not listening to him. Or at least they are not hearing what he has to say.

In the weeks since the terrorist attacks in Paris, Obama has stressed in speech after speech that U.S. law enforcement and homeland security officials are “relentless.” He has insisted the country remains “strong” and ­“resilient.”

Sunday night was no different. The president described his strategy as “strong and smart, resilient and relentless.”

Obama didn’t use the prime-time speech to outline any major shifts in the battle against the Islamic State, which he has repeatedly said will take years to complete and will not involve large commitments of U.S. ground troops. Nor did he propose any major new domestic security initiatives.

Instead, he sought to calm a fearful American public, increasingly worried about the possibility of another terror attack and concerned about the Islamic State’s resilience after more than a year of airstrikes from the U.S. military.

“The threat from terrorism is real,” Obama said. “But we will over come it. Our success won’t depend on tough talk or abandoning our values or giving in to fear.” Instead, Obama pledged to be steadfast and stick with his current plan.

The absence of big new policy proposals from the president reflects the lack of any low-cost or tidy solutions to ease the concerns of the American people after a string of deadly attacks over the past month. The Islamic State’s core leadership in Syria played a role in planning the attack in Paris and the bombing of a Russian jet over Egypt’s Sinai Peninsula, according to intelligence reports.

In San Bernardino, the attackers appear to have been inspired by Islamic State propaganda online but were not part of an organized group, Obama said. Such homegrown attacks by self-radicalized individuals are notoriously resistant to detection by U.S. intelligence services and are designed to provoke division and a backlash against Muslims.

The president described them as a “new phase” in American’s nearly 15-year-long fight against terrorism.

Even as he acknowledged Americans’ worries, Obama warned of the danger of rhetoric that broadly demonizes American Muslims or plays into the Islamic State’s narrative of a war between Islam and the West. His address was designed to counter what White House officials described as run of xenophobic speeches and statements on the campaign trail by Republican candidates, including Donald Trump and Ben Carson.

President Obama addressed the attacks in San Bernardino, Calif., and overseas from the Oval Office. (Associated Press)

Obama called on Americans to reject religious tests for Syrian refugees, which have been suggested by some Republican presidential candidates, and proposals that treat Muslim Americans differently. “When we travel down that road we lose,” Obama said. “That kind of divisiveness betrays our values” and aids the Islamic State.

Obama faced a significantly larger challenge in making the case for his multiyear strategy to defeat the Islamic State in Iraq and Syria at a time when many Americans have begun to doubt his resolve and Republican hopefuls are promising quick, violent solutions.

Since the Paris attacks, the administration has intensified its military campaign, deploying small numbers of Special Operations forces to Iraq and Syria and increasing the pace of airstrikes, especially on Islamic State oil infrastructure. In recent weeks, U.S. officials said they had destroyed 116 oil tank trucks, which provide critical revenue to the group.

Obama touted the thousands of airstrikes targeting the Islamic State’s leaders, troops and equipment as proof of the campaign’s intensity. He also spoke of stepped-up intelligence efforts, better training of local forces and his administration’s closer cooperation with Turkey to seal its southern border with Syria.

The strategy has the full support of America’s military commanders and counterterrorism experts, he said.

So far, though, that strategy has produced mixed results. Even with the help of U.S. air power, Iraqi forces haven’t been able to retake any major cities from the Islamic State. The first forces trained by the U.S. military in Syria were completely overmatched by their more-radical foes.

Obama has responded by counseling patience, warning that a big influx of U.S. forces into the two countries would simply lead to another long and costly war.

The lack of clear progress on the ground and increasingly bellicose rhetoric from presidential candidates has fed doubts about whether the president is fully committed to destroying the group. Obama has contributed to some of those doubts with his own rhetorical missteps.

When the Islamic State was gaining momentum and taking territory, Obama dismissed the group as the junior varsity to al-Qaeda. Only days before the Paris attacks, he said that the Islamic State had been “contained.” Administration officials said the president was referring specifically to the group’s ability to seize new ground in Iraq and Syria.

But the administration’s critics seized on the remarks as proof that the president was out of touch. Even allies, such as Democratic presidential front-runner Hillary Clinton, have criticized Obama for not acting more swiftly and aggressively in Syria.

Obama has responded to the critiques by warning that an overreaction to the 9/11 terrorist attacks led the United States to rush into an unwise war in Iraq. “I think we made some bad decisions subsequent to that attack, in part based on fear, and that’s why we have to be cautious about it,” he said two weeks ago while visiting Asia.

Today, Obama faces a situation that is somewhat analogous to that of his predecessor, George W. Bush. After years of U.S. casualties and costly setbacks, Americans by 2006 had begun to question whether Bush understood the conflict. He responded with a new strategy that involved the deployment of more than 30,000 additional soldiers and Marines.

There are far fewer American soldiers in harm’s way today than in 2006 and 2007, when more than 100 U.S. troops were being killed each month and Bush faced heavy pressure to withdraw U.S. forces.

Now the pressure is on Obama to escalate a war that he had hoped to end. His response has been to appeal to Americans’ inner strength. “Let’s not forget what makes us exceptional,” Obama said. “Let’s not forget that freedom is more powerful than fear.”

Juliet Eilperin contributed to this report.