U.S. President Donald Trump announced on Thursday that Secretary of Defense James Mattis will leave his post in February.

“General Jim Mattis will be retiring, with distinction, at the end of February, after having served my Administration as Secretary of Defense for the past two years,” posted Trump on Twitter. “During Jim’s tenure, tremendous progress has been made, especially with respect to the purchase of new fighting equipment.”

“General Mattis was a great help to me in getting allies and other countries to pay their share of military obligations,” he added. “A new Secretary of Defense will be named shortly. I greatly thank Jim for his service!”

This development comes as Trump said on Wednesday that the United States will withdraw its troops from Syria. Mattis, a former Marine, disagreed with the decision and advised the president against it.

Additionally, Mattis saw himself at odds with some of Trump’s positions, including exiting the Iran deal and moving the U.S. embassy in Israel from Tel Aviv to Jerusalem. However, during his tenure as secretary of defense, Mattis also continued the Pentagon’s longstanding warm relationship with Israel.

When Trump picked Mattis, who was relieved as head of U.S. Central Command under President Barack Obama for reportedly disagreeing with the administration’s posture on Iran, to be the Pentagon chief shortly after he won in 2016, mixed reactions came from the pro-Israel community.

“The ZOA is concerned about the potential appointment of Marine General James Mattis as Secretary of Defense and urges that Mattis not be appointed,” said the organization in a press release. “Mattis’s statements at a 2013 Aspen Institute conference were hostile to Israel, and revealed a lack of appreciation for and understanding of the extraordinary value to American security resulting from a strong American-Israeli alliance and a secure Israel.”

These statements included, but not limited to, “We have got to find a way to make the two-state solution” and that “I paid a military security price every day as the commander of CENTCOM because the Americans were seen as biased in support of Israel, and that moderates, all the moderate Arabs who want to be with us, because they can’t come out publicly in support of people who don’t show respect for the Arab Palestinians.”

He also said, “If I’m Jerusalem and I put 500 Jewish settlers out here to the east and there’s 10,000 Arab settlers in here, if we draw the border to include them, either it ceases to be a Jewish state or you say the Arabs don’t get to vote—apartheid. That didn’t work too well the last time I saw that practiced in a country.”

However, organizations such as the Republican Jewish Coalition supported the nomination.

“The selection of General Mattis to serve as Secretary of Defense is a smart and important decision by President-elect Trump,” Republican Jewish Coalition executive director Matt Brooks said in a statement. “Throughout his career, General Mattis has made the protection of the United States, our assets and our allies around the world his top priority. General Mattis believes in a strong U.S. military posture and understands the threats we face, like a newly aggressive Iran. He has the type of worldview the leader of our Defense Department needs.”

Although it did not formally endorse the pick, the Jewish Institute for National Security of America defended Mattis, regardless of his past controversial statements on Israel.

“We feel compelled to convey that characterizations of one candidate, General James N. Mattis, USMC (ret.), as anti-Israel are ill-founded and unfair,” said JINSA president and CEO Michael Makovsky in a statement.

“We understand and share many of the objections to his remarks, including that he seemed to blame mostly Israel for the impasse, despite the critical challenges it faces in lacking a stable, moderate Palestinian partner that genuinely seeks a durable peace with the Jewish state,” he added. “Some American Jews and even Israelis make the same mistake. In any case, he has not repeated those remarks.”

Makovsky also said that “General Mattis’ outlook on these issues aligns perfectly with Israel’s, which considers an aggressive Iran its greatest strategic threat, and a nuclear Iran to be an existential threat. Israel also seeks a strong U.S. presence in the Middle East.”

“General Mattis has noted this alignment of views with Israel, and correctly explained the synchronization of Israeli and Arab outlooks on these subjects,” he added. “This should be heartening to the overwhelming majority of Americans who believe that a strong State of Israel is necessary for its own sake and important for a strong America.”

During his confirmation hearing, the former general told the Senate Armed Services Committee that the capital of Israel is Tel Aviv, and that he would support the two-state solution “if that brings peace to the Middle East.” He gave his endorsement of the U.S.-Israel relationship and agreed that Hamas is a terrorist group.

Despite his disagreements with the president on Iran and the embassy move, Mattis proved to be a friend of Israel at the Defense Department.

As secretary, he made his only visit to Israel in April 2017, spending two days there. He met with Israeli officials such as Prime Minister Benjamin Netanyahu, President Reuven Rivlin and then-Defense Minister Avigdor Lieberman.

U.S. Secretary of Defense Jim Mattis with Israeli Prime Minister Benjamin Netanyahu in Israel in April 2017. Credit: U.S. Embassy in Israel.

“We are committed to Israel’s defense,” said Mattis while meeting with Rivlin. “We support Israel’s internal security and Israel’s external security.”

“We’re not alone in how we look at terrorists. We’re not alone how we look at Iran’s problems, so it’s time for us to all work together,” he added. “But certainly the enduring relationship with Israel will be stronger every day.”

In a joint press conference with Lieberman, Mattis said: “Iran continues to threaten Israel and its neighbors with ballistic missiles through its maritime and cyber activities and through proxies and surrogates, including Lebanese Hezbollah, a terrorist organization helping to keep [Syrian dictator Bashar Assad] in power in Syria.”

Defense Secretary Jim Mattis and Israeli Defense Minister Avigdor Lieberman host a joint press conference at the Israeli Ministry of Defense in Tel Aviv on April 21, 2017. Mattis is the first cabinet member from the new administration to visit Israel. Credit: Air Force Tech. Sgt. Brigitte N. Brantley/U.S. Department of Defense.

Mattis said in February that Israel has “an absolute right to defend themselves. They don’t have to wait until their citizens are dying under attack before they actually address that issue.”

“It is interesting that everywhere we find trouble in the Middle East, you find the same thing behind it. Whether it be in Yemen or Beirut, or in Syria, in Iraq, you always find Iran engaged,” he added. “If you’re in Bahrain, and the police there have captured explosives and that sort of thing, clearly from Iran; if you’re picking up debris in Saudi Arabia of Iranian missiles; or you’ve got explosive boats, remote-controlled boats, out in the Red Sea, you can see where Iran is either producing the wherewithal for the fight or actually leading the fight, in some case.”

In April, Mattis received Lieberman at the Pentagon, where the two reportedly talked primarily about the Iranian threat.

During his tenure, Mattis repeatedly warned Iran against threatening the U.S. and its allies. Four months ago, he put the regime “on notice.”

“Iran has been put on notice that the continued mischief they’ve caused around the area, murder they have caused,” he said, according to The Independent.

In September, in response to Iranians chanting “Death to the U.S.” and “Death to Israel,” Mattis said,“It would be good if they knew what they were talking about,” in addition to expressing hope that “cooler and wiser heads would prevail.”

How the departure will affect the U.S.-Israel relationship has yet to be determined, though the Defense Department has historically been friendly toward the Jewish state.

“It’s likely not going to have a huge impact on the U.S.-Israel relationship,” Jonathan Schanzer, senior vice president of research at the Foundation for Defense of Democracies, told JNS. “The relationship, I think, is deep in bureaucratic ways throughout the Pentagon.”

Schanzer added that “Syria seems to have played a significant role” in addition to both a possible withdrawal of troops from Afghanistan and a partial U.S. government shutdown.

As to who might replace Mattis, names that have been floated include, but are not limited to, Sen. Tom Cotton (R-Ark.), former Sen. Jim Talent (R-Mo.) and former Gen. Jack Keane. During the transition after the election, Keane was offered the role of Sec. of Defense but declined, citing dealing with personal matters. Keane recommended Mattis to Trump.

Nonetheless, Mattis’s replacement, Schanzer said, will “have to re-establish ties with allies across the Middle East and perhaps even beyond who have been rattled by the Syria decision,” which he said will be “a huge challenge.”

“I think the issue of deterrence will also be an important one given that the Syria move really has emboldened some of America’s fiercest adversaries: Russia, Iran, Hezbollah, [Syrian President Bashar Assad’s] regime,” he added.

The American Israel Public Affairs Committee declined to comment.

However, the Republican Jewish Coalition and the Endowment for Middle East Truth saluted Mattis amid the announcement. Even the Zionist Organization of America appeared to change its attitude toward him.

“We’re sad to see Secretary Mattis go, but are deeply grateful for his lifetime of service to our country,” RJC spokesperson Neil Strauss told JNS. “Specifically, we want to commend his work as Secretary of Defense strengthening U.S.-Israel security cooperation, and his great start on the process of rebuilding our military after the erosion during the Obama administration.”

“We appreciated [his] calling Israel’s operation to block Hezbollah’s tunnels into Israel ‘exactly the right thing to do,’” ZOA president Mort Klein told JNS. “He also noted ‘It would be irresponsible if Israel did not undertake this operation and protection of their own territorial integrity and their own populations.’”

“ZOA also shares Mattis’ concerns about the early exit of American troops from Syria,” he continued. “The withdrawal could dangerously enhance the positions of Iran, ISIS, Hezbollah and other malign actors. ZOA joins the president in thanking Secretary Mattis for his service to our country.”

“General James Mattis will be remembered as a true hero for resigning over the president’s precipitous and feckless decision to abruptly pull all of our troops out of Syria,” EMET founder and president Sarah Stern told JNS. “It is a terrible shame that the president had consulted with the Turkish autocrat, Recep Tayyip Erdoğan, about this move before consulting with his own Cabinet.”

She continued, “When he explained in his resignation letter that ‘One core belief I have always held is that our strength as a nation is inextricably linked to the strength of our unique and comprehensive system of alliances and partnerships,’ I feel he is echoing the feeling that many of us share that we have abandoned  and betrayed the Kurds who had shed their blood together with us fighting ISIS in Syria, and now we are feeding him to the Turkish wolves.”

“General Mattis has a true understanding of the region, and an appreciation of the nature of the true threats in the region, especially Iran,” added Stern. “He will be sorely missed.”