Charles Krauthammer said on "Special Report" that if Jeb Bush wants to win the presidency in 2016, he will have to be critical of the foreign policy decisions of his older brother, former President George W. Bush. 

Earlier this week, Jeb Bush started the process of trying to lay out a foreign policy position that is separate from his father and brother.

"I'm my own man, and my views are shaped by my own thinking and my own experiences," Bush said.

During the All-Star Panel discussion, Krauthammer said he believes that Jeb Bush will have to put aside any hesitance to talk about foreign policy mistakes made during the Bush administration.

"The country has to know what he thinks about the past and he's gonna have to be critical of - if he is - the policies of the past. Otherwise he's trapped in a place where he can't say what his ideas are and if he can't, he won't prevail," said Krauthammer, adding that the former Florida governor doesn't need to launch an "Obama-like" attack on Bush 43, but can say "we made mistakes."

Tucker Carlson said any presidential candidate will have to address a threshold question of "what have you learned" since the Iraq War. 

"This fantasy that overthrowing dictators leads to a better world inevitably. Is that true? And a whole bunch of other questions," said Carlson, arguing that any candidate that can't answer those questions will have "no credibility."

Krauthammer said 2016 will be a rare presidential race because foreign policy will be at the forefront. 

He said the Obama administration's foreign policy failures have left a "ripe" opportunity opening for Republicans. 

"We are at one of the lowest ebbs in terms of our standing in the world, the trust of our allies and the fear of our enemies," said Krauthammer, praising Marco Rubio for making the strongest case so far on foreign policy. 

Krauthammer said Sen. Rand Paul (R-Ky.) represents the other "extreme," but that his positions were more popular before the rise of ISIS. 

"It's gonna be a hard argument. He was a lot more popular a year and a half ago when he stood up in the Senate for 11 hours and protested the droning of an al Qaeda American in Yemen. I'm not sure he would do that again today," he said.

Ron Fournier agreed that foreign policy will be the dominant issue in 2016, saying it will be "really tough" for Hillary Clinton due to criticism of her performance as secretary of state.

Watch the full discussion above, and tune in at 6p ET weeknights for more analysis from the panel on "Special Report."