Obama's Final Press Conference of 2015

President Obama opened his last press conference of the year on Friday with a joke.

“Clearly, this is not the most important thing that’s taking place in the White House today,” the president said. “There’s a screening of Star Wars.”

Before Obama left to watch the highly anticipated film at the White House—where he won’t have to wait in line for hours, unlike the rest of the American public—he spoke to reporters in the briefing room for just over an hour, starting with a list of his administration’s wins from this year: a national unemployment rate below 6 percent, the Supreme Court’s decisions on gay marriage and Obamacare, the climate-change deal, and no end-of-year government shutdown.

“I have never been more optimistic about a year ahead than I am right now,” Obama said. “And in 2016, I’m going to leave it all on the field.”

But the specter of foreign terrorist organizations and their growing reach looms large over the nation as it inches toward the new year, and the president has spent the last several weeks attempting to assuage a public whose fears of an attack have reached post-9/11 levels.

"You told the nation there’s no specific or credible threat of a similar attack, but how is it really possible to know?” one reporter asked Obama. “Aren’t similar plots going to be just as hard to detect beforehand?”

“You’re absolutely right,” replied Obama, who travels later Friday to California, where he’ll meet privately Friday with the families of the San Bernardino shooting, whose perpetrators were allegedly inspired by the Islamic State. He noted the difficulty of screening for self-radicalized individuals in the U.S.

“This is a different kind of challenge than the sort that we had with an organization like al-Qaeda that involved highly trained operatives who are working as cells or as a network,” Obama said.

The president reiterated his belief the United States will defeat the Islamic State, which it has been bombing for more than 18 months in Iraq and Syria. He also vowed to follow through on one of his first campaign promises: Shutting down Guantanamo Bay, the facility in Cuba that holds detainees captured in the war on terrorism. Obama called the prison camp “one of the key magnets for jihadi” recruiters seeking to “create this mythology that America is at war with Islam.”

Obama dodged a question about whether he believes the presidency of Syria’s Bashar al-Assad will outlast his own, saying, “I think that Assad is going to have to leave the country to stop the bloodletting or for all the parties involved to be able to move forward in a nonsectarian way.”

Obama called the government funding bill passed by Congress Friday morning “a good win.”

“There are some things in there that I don’t like, but that's the nature of legislation and compromise,” he said. “I think the system worked. That gives me some optimism that next year on a narrow set of issues we can get some more.”

Obama said he is “hopeful” about sentencing reform making its way through Congress next year. Before the news conference, he commuted the sentences of 95 drug offenders, the third time this year he has used his clemency power to release individuals who received sentences now considered harsh for drug crimes.

After his visit to San Bernardino Friday night, Obama and the rest of the first family head to Hawaii for their annual two-week vacation.

“I have to get to Star Wars,” he said as he left the briefing room, waving.