In an interview on Fox News’ “The O’Reilly Factor” Wednesday, Giuliani blamed Hillary Clinton for the rise of ISIS. “Hillary Clinton could be considered a founding member of ISIS,” Giuliani said.

The Republican said that Clinton’s position as secretary of state during the American withdrawal from Iraq and restrained response to the Syrian conflict gives the Democratic presidential candidate at least partial responsibility for the terrorist group. Giuluni criticized Clinton for “being part of an administration that drew twelve lines in the sand and made a joke out of it.”

ISIS has become a dominating talking point in the primary election in the aftermath of the terrorist attacks that rocked Brussels on Tuesday. Clinton called for increased air power in Iraq and Syria to battle the terrorist group and the enlistment of tech companies to more effectively battle ISIS on social platforms in a speech on Wednesday. The Democrat sharply criticized Ted Cruz and Donald Trump’s proposals to crack down on Muslim communities in America, calling the Republicans “loose cannons.”

Giuliani praised Cruz and Trump for their stances on ISIS and, while he hasn’t endorsed either candidate, told O’Reilly that Trump “looks like the best one.”