In a late-night tweet, Trump called Rice "a disaster" after she criticized Trump's Syria strategy on the HBO show.
But things didn't stop there. Rice responded on Twitter just minutes later, accusing Trump of giving her a "totally gross" hug when they met at the White House Correspondents' Dinner in 2015.
"Susan Rice, who was a disaster to President Obama as National Security Advisor, is now telling us her opinion on what to do in Syria," Trump tweeted Friday night. "Remember RED LINE IN THE SAND? That was Obama. Millions killed! No thanks Susan, you were a disaster."
Trump's "red line" reference was in regard to Obama's warning to Syrian leader Bashar al Assad not to use chemical weapons against his own people, then Obama's unwillingness to take action against Assad when the Syrian leader defied Obama's warning.
About 16 minutes later came Rice's response:
"Then why did you come up and hug me at 2015 WHCD when I’d never met you (which was totally gross) and whisper in my ear that I had been 'very unfairly treated' over Benghazi and 'was doing a great job for the country'?"
Earlier in the evening, Rice told Maher that Trump had given the leaders of Russia, Syria and Iran a "green light" to do as they please in northern Syria by planning to remove U.S. forces from the region -- and warned of an emboldened ISIS.
"What Trump has done in Iraq and now Syria is in effect to cede a portion of northern Syria, Kurdish homeland, to the Turks and to evacuate the Americans as if it's his Saigon," Rice told Maher, referring to the U.S. pullout from Vietnam in the 1970s.
"We've left our Turkish allies homeless," she continued. "They're now going scattered throughout the region. We've given Assad and Putin and the Iranians a green light to take over that territory that they've been long wanting to take. And ISIS is going to come back."
During his interview with Rice, Maher brought up the 2012 terror attack in Benghazi, Libya, suggesting to Rice that the situation with Turkey and the Syrian Kurds "must infuriate" her because Republicans don't seem as upset over Syria as they were when an American ambassador and others were killed in Benghazi -- a situation that many in the GOP have blamed on then-Secretary of State Hillary Clinton.
Rice who was promoting her book, "Tough Love," called Benghazi a "horrible tragedy" before addressing the ramifications of Trump's troop withdrawal.
"But what we're going to lose as a result of what Donald Trump has done in Syria is, we're going to have a whole terrorist resurgence as a result of his pullout," Rice said. "So we'll see the ramifications of that in [the loss of] American and Allied lives, I think I'm afraid, for years to come."
The former Obama administration official also told Maher that Russian President Vladimir Putin was benefiting from America's political infighting, adding that in her view the "domestic political divisions" in the U.S. were "our greatest national security vulnerability."
"What is I think happening now -- and what Putin's genius is -- is that he understands that we are so divided internally and that ... we can't get stuff done," Rice said. "All Putin had to do was jump in and exacerbate those divisions, pour salt in the wounds."
Rice compared the divisiveness in the U.S. to a "flesh-eating disease" before adding, "I think we have the ability to fix it. It's a problem of our own making, our domestic divisions, where we have to stop hating each other."