Rudy Giuliani amped up the rhetoric on Wednesday night, saying Hillary Clinton "could be considered a founding member of ISIS."

Speaking on "The O'Reilly Factor ," the former New York City mayor claimed Clinton bears responsibility for creating the terrorist organization, which controls parts of Syria and Iraq, because she was secretary of state during President Barack Obama 's first term.

"She helped create ISIS," Giuliani said. "Hillary Clinton could be considered a founding member of ISIS."

Asked how that makes her responsible by host Bill O'Reilly, Giuliani elaborated:

By being part of an administration that withdrew from Iraq. By being part of an administration that let [former Prime Minister Nouri al-] Maliki run Iraq into the ground, so you forced the Shiites to make a choice. By not intervening in Syria at the proper time. By being part of an administration that drew 12 lines in the sand and made a joke out of it."

O'Reilly pointed out that Clinton couldn't force policy on President Obama. Her only option, he said, would have been to resign.

"Yeah -- which is what a patriot does," Giuliani replied.