Announced October 6, US President Trump’s abrupt withdrawal of troops from northeast Syria sent shock waves throughout the Middle East, including Israel. In the wake of that decision, and in spite of the ethnic cleansing resulting from it, many pro-Israel Christians have adopted a visceral embrace of what Trump did.The warning signs to Jerusalem are sobering. Trump justified his decision in sweeping terms. Tweeting on October 9, he wrote, “The United States has spent eight trillion dollars fighting and policing in the Middle East. Going into the Middle East is the worst decision ever made in the history of our country!”It is an argument he continued to emphasize: “Fighting between various groups that has been going on for hundreds of years. USA should never have been in Middle East. The stupid endless wars, for us, are ending!”Five days later, he continued his theme. “The same people who got us into the Middle East mess are the people who most want to stay there!” he tweeted on October 14.Was there a policy guiding Trump’s decision? Bereft of a national security adviser, fired in September, and derisive of his own State Department, Trump nonetheless has a foreign policy. He tweeted it on October 7, “If Turkey does anything that I, in my great and unmatched wisdom, consider to be off-limits...”Square in the middle of the Middle East along with its sworn enemy, Iran, Jerusalem did not miss the message. Speaking on October 10 at a memorial service for Israelis who died in the 1973 Yom Kippur War, Prime Minister Netanyahu expressed lessons learned. His remarks were also an unmistakable reaction to Trump’s withdrawal from Syria and the threat it poses to Israel.“We do not aspire to be ‘a people that dwells alone’ but thus we were forced to stand at the start of the Yom Kippur War; only towards the end did the American aid arrive,” he said. “Like in 1973, today we very much appreciate the important support of the US, which has greatly increased in recent years, as well as the major economic pressure that the US is using on Iran.”“Even so, we will always remember and implement the basic rule that has guided us; Israel will defend itself, by itself, against any threat,” he continued.It is highly unlikely that Trump did not know about or understand Israel’s concerns in the aftermath of withdrawal from Syria and his tweets deriding US involvement throughout the Middle East. Eschewing any reassurance in his daily Twitter blasts, the president’s only bone of consolation was in a political rally on October 14. In the context of combating antisemitism from the left, he declared, “My administration is confronting this scourge, and we’re standing with our close friend and partner, the State of Israel.”The scourge of antisemitic rhetoric from the US Left is not a surprise. The surprise is that it is erupting among mainstream evangelicals too.TruNews is one of the most popular YouTube “news” channels targeting conservative Christians in the States. Its almost daily broadcasts have been viewed more than 20 million times. Among the most popular reports are these: “Israel Plans to Build the Third Temple and a Tower of Babel?”; “Trumped Up Prophecies: How Kabbalah Wizards & Christian Zionists Are Trying to Build a Third Temple”; and “Your Father is the Devil: Zionist Jews Demand Censorship of New Testament Holy Bible.”Replete with the most explicit expressions of antisemitism expressed in the last one hundred years, the polished presentations are winning hearts among Israel’s largest demographic base of support outside Diaspora Jews.“They are relentless in vilifying Israel and listeners are wavering; I regularly get asked about things they say,” says John Haller, an attorney and geopolitical analyst based in Columbus, Ohio. His own pro-Israel “Prophecy News Update” on YouTube reaches tens of thousands each week.The problem among Haller’s constituency – and my own – is that many of them are vicious when challenged by Trump’s abandonment of US allies to ethnic cleansing.Charges of moron, fool and traitor are regularly hurled in response to reasoned arguments against Trump’s action. Even more disturbing, however, are descents into antisemitic rhetoric.Reacting to a Facebook post of a Israeli media story about a Syrian family that feels betrayed by the US, an ostensibly pro-Israel Christian, his account replete with Israeli symbols, wrote this:“Why doesn’t Israel move in along with NATO and save those Christians??? Oh that’s right the Jewish people don’t like the Christina [sic] because as per the Jew they are a demonic cult religion.”When I confronted the now former “friend,” another one rebuked me for doing so. “Don’t feel so right, Brian, [about] different opinions [that] you cut off. Even if they are not correct or a little abusive, that’s how we all learn.”And in response to an article by Jerusalem Post journalist Seth Frantzman, another pro-Israel “friend” responded with the graphic depiction of a rat, basing the depiction an acronym for “Republicans Against Trump.” When confronted with the disturbing allusion to classic antisemitic imagery, I was promptly de-friended.In short, Netanyahu was more right than perhaps he knew. Financial and verbal support from Israel’s strongest allies, the United States and conservative evangelicals, is wonderful. But when called upon to act on Israel’s behalf, it can transfigure into something else and do so in a flash.If that happens – when that happens – indeed, Israel will have to defend itself by itself against any threat.The writer is a journalist living in Israel. He is editor-in-chief of the Jerusalem Journal and its primary publication, the Chaim Report, at ChaimReport.com.