Hillary Clinton faces first real challenges at Iowa Democratic debate

On the Paris attacks, all three agreed that ISIS must be dealt with and called on the U.S. to be an active — but not sole — participant in that fight.

“We have to look at ISIS as the leading threat of an international terror network,” Clinton said. “It cannot be contained, it must be defeated.”

In the same answer, however, Clinton also showed agreement with the White House.

“It cannot be an American fight,” she said. “The president has said, and I agree, we must take the fight to ISIS.”

The attacks Friday in Paris that left more than 100 dead and the world in shock prompted an immediate shift in this debate and the larger campaign for the White House. CBS News changed its plans and made foreign policy and security the first focus of the two-hour debate.

The focus on Paris also provided Sanders opportunity to draw a new contrast between Clinton and him. Sanders opposed the 2003 invasion of Iraq and voted against authorizing it. Clinton voted in favor, something Sanders was sure to make clear.

“She said something like the bulk of the responsibility is not ours,” Sanders said. “In fact, I would argue that the disastrous invasion of Iraq, something I strongly opposed, has unraveled the region completely and led to the rise of Al-Qaeda and to ISIS.”

Clinton countered that she has said the Iraq invasion was “a mistake,” but said America must realize it “has antecedents to what happened in Iraq and we have to be vigilant about it.”

Still, Sanders and former Maryland Gov. Martin O’Malley agreed with Clinton that the U.S. cannot go it alone.

“There is widespread agreement here,” he said. “The United States cannot do it alone. Muslim nations in that region have to fight.”

Visit myajc.com later for full coverage of the Democratic debate.