Brennan, who served as CIA director from 2013 to 2017, tweeted on Friday that the killing was a “criminal act and “highly reckless.”
He added that Iran should wait for President-elect Joe Biden to be sworn in, saying it would be wise to “wait for the return of responsible American leadership” and to “resist the urge to respond against perceived culprits.”
He added that the killing is a “flagrant violation of international law” and could “encourage more governments to carry out lethal attacks against foreign officials.”
Cruz then responded to Brennan, saying it’s “bizarre to see a former head of the CIA consistently side with Iranian zealots who chant ‘Death to America.’ And reflexively condemn Israel. Does Joe Biden agree?”
Brennan then responded, saying “Your lawless attitude & simple-minded approach to serious national security matters demonstrate that you are unworthy to represent the good people of Texas.”
The former CIA head then followed up with a series of jabs at Cruz, calling him a “poor Senator and a bad lawyer.”
“My commitment to Israel’s security & my efforts to counter Iran’s malign activities are well documented throughout my 33 years of national security work serving Republican & Democratic Administrations,” he said.
“Aside from his tiresome rhetoric, what has Senator Cruz ever done?”
The New York Times reported on Friday that Fakhrizadeh was believed to be leading Iran’s nuclear program for two decades and kept working after the military effort quietly ended in the early 2000s.
Iran’s Supreme Leader Ayatollah Ali Khamenei said on Saturday that his first priority was the “definitive punishment of the perpetrators and those who ordered it,” The Associated Press reported.
The alleged assassination comes toward the end of President Trump’s time in office, as he was recently dissuaded from striking the nation to halt its military program. It could also make it more difficult for Biden to reenter the Iran nuclear deal, which Trump withdrew from two years ago.