Former Secretary of State Rex Tillerson said Israeli officials “played” President Donald Trump. He claimed that when dealing with Israeli Prime Minister Benjamin Netanyahu “it’s always useful to carry a healthy amount of skepticism.”

During a panel discussion Tuesday at Harvard, Tillerson said, “They did that with the president on a couple of occasions, to persuade him that ‘we’re the good guys, they’re the bad guys’.”

Netanyahu responded via tweet saying “Israel *is* the good guy.”

Tillerson, who repeatedly clashed with Trump over foreign policy, was fired in March after calling Trump “a moron,” making him the first cabinet official to ever be fired over social media.

While Trump wholly supported Netanyahu’s leadership, Tillerson described the Israeli Prime Minister as “an extraordinarily skilled” politician and diplomat, but also “a bit Machiavellian.”

In his Harvard talk, Tillerson preached a form of foreign diplomacy based on negotiation and compromise.

“Every successful negotiation is defined as both parties leaving with an acceptable outcome,” he said. “If you ever think about a negotiation as a win/lose, you’re going to have a terrible experience, you’re going to be very dissatisfied, and not very many people are going to want to deal with you.”

After Trump’s son-in-law, Jared Kushner, was appointed to design a peace plan for the Middle East, Kushner decided to give up the term “two state solution” and recognize Jerusalem as Israel’s capital. The U.S. embassy has since relocated from Tel Aviv to Jerusalem.

“If you say ‘two-state’, it means one thing to the Israelis, it means one thing to the Palestinians,” said Kushner at the Washington Institute for Near East Policy. “We said, you know, let’s just not say it. Let’s just say, let’s work on the details of what this means,” he said.

The U.S. has practically severed all relations with Palestine by stopping funding the United Nations agency that helps Palestinian refugees, slashing hundreds of millions of dollars in aid for projects in the Gaza strip and cutting funding to hospitals in Jerusalem that serve Palestinians.

The future of Israeli and Palestinian policy is uncertain, as Netanyahu’s chief rival, Benny Gantz, declared victory after a narrow vote tally on Thursday showed his party winning a first-place finish in this week’s parliamentary elections.

Gantz is left-leaning compared to Netanyahu and criticized his decision to block U.S. Congresswomen Ilhan Omar (D-Minnesota) and Rashida Tlaib (D-Michigan) from entering Israel.