'Palestine from the river to the sea' means 'extermination' of Israel: ex-counterterrorism official

When pro-Palestinian protesters chant "Palestine from the river to the sea," they are really calling for the "extermination of the Jewish state," one former counterterrorism coordinator warned.

"They think that Israel shouldn't exist at all," Nathan Sales told "Sunday Night in America." "This is exterminationist rhetoric and our First Amendment means that we have to tolerate this kind of speech, but the antidote for that kind of abhorrent speech is more speech. We need to expose what these Hamas sympathizers are really all about."

Several American cities have seen protests against Israel by pro-Palestinian supporters since the Oct. 7 attack by Hamas. Instead of condemning Hamas, many have spoken out against Israel for military operations in besieged territory, citing civilian casualties. 

Sales said now is the time Americans must "stand strong with Israel."

"The attack ... [is] the worst day for Israel in its 75-year history. It's the worst slaughter of Jews since the Holocaust. We've said, ‘Never again.’ Well, now is the time to show that we mean it and the way you show that you mean it is at least being out in the streets and showing support for Jews who are now looking over their shoulders and fearing for their lives."