It is precisely at moments like this that an American president should speak up directly on behalf of the American creed.

On November 15, 2015, as the world grappled with the horrors of a multipronged ISIS attack in Paris, Donald Trump, who was then an improbable but officially declared candidate for the presidency, tweeted, “When will President Obama issue the words RADICAL ISLAMIC TERRORISM? He can’t say it, and unless he will, the problem will not be solved!”

I raise the subject of this tweet, and the sentiment that motivated it, in light of President Trump’s remarkable reaction to the violence in Charlottesville, Virginia, this weekend. “We condemn in the strongest possible terms this egregious display of hatred, bigotry and violence on many sides, on many sides,” he said. Trump, when presented with the chance to denounce, in plain, direct language, individuals who could fairly be described as “white supremacist terrorists,” or with some other equivalent formulation, instead resorted to euphemism and moral equivalence.

Trump’s position on the matter of President Obama’s anti-terrorism rhetoric did not place him outside the Republican mainstream. Obama’s critics argued throughout his presidency that his unwillingness to embrace the incantatory rhetoric of civilizational struggle—his reluctance to cast such groups as al-Qaeda and ISIS as vanguards of an all-encompassing ideological and theological challenge to the West—meant that, at the very least, he misunderstood the nature of the threat, or, more malignantly, that he understood the nature of the threat but was, through omission, declaring a kind of neutrality in the conflict between the United States and its principal adversary.

It is true that Obama calibrated his rhetoric on the subject of terrorism to a degree even his closest advisers sometimes found frustrating. They hoped that, on occasion, he would at least acknowledge the legitimacy of Americans’ fears about Islamist terrorism before proceeding to explain those fears away. But Obama had a plausible rationale for avoiding the sort of language his eventual successor demanded that he deploy. He believed that any sort of rhetorical overreaction to the threat of Islamist terrorism by an American president would create panic, and would also spark a xenophobic response that would do damage to America’s image, and to Americans Muslims themselves.

He also took a view opposite to that of Donald Trump: Bringing Islam itself to the forefront of the conversation about terrorism would create a backlash in the Muslim world that would do real harm to the armed anti-terrorism campaigns he was then leading. Obama, over the eight years he served as president, ordered the killings of more Muslim terrorists, in more Muslim countries, than any of his predecessors. On this subject, he spoke so softly he could barely be heard, but he carried a lethal stick. His goal was to eradicate Muslim terrorists without alienating the great mass of Muslims unsympathetic to the theology and tactics of those terrorists.

I spoke with Obama on a number of occasions about the dilemmas he faced in his fight against Islamist terror. I was one of those who thought he was rhetorically wanting, but I also came to understand that he labored under no illusions about the nature of the threat, and of the problem afflicting Islamic civilization. There is a need, he told me once, for “Islam as a whole” to challenge the radicals, “to challenge that interpretation of Islam, to isolate it, and to undergo a vigorous discussion within their community about how Islam works as part of a peaceful, modern society.” Refracting this conflict through the prism of a “clash of civilizations” of the sort imagined by the late political scientist Samuel Huntington would do no one any good. “I do not persuade peaceful, tolerant Muslims to engage in that debate if I’m not sensitive to their concern that they are being tagged with a broad brush,” Obama said.

Muslim radicals do seek the sort of civilizational clash that Obama tried to avoid, but reality has delivered them something else: A clash within their civilization, between fundamentalists and modernizers, between a small but murderous minority and a much larger number of Muslims who seek to co-exist with other cultures and religious groups. It is up to the worldwide community of Muslims, Obama believed, to shape the Muslim future. It was not the job of the president of the United States to insert himself unnecessarily into this debate, by using rhetoric that would be polarizing and dangerous.

Trump, in his remarks on Saturday, refused to align himself against the so-called alt-right protest movement. His decision to maintain a neutral stance on the activities of the racist and anti-Semitic right has opened him to charges of hypocrisy; Trump is now refusing to speak plainly about the nature of a particular terrorist threat, a sin he continually ascribed to his predecessor.

But the issue here is substantially larger than mere hypocrisy. Obama carefully measured his rhetoric in the war against Islamist terrorism because he hoped to avoid inserting the U.S. into the middle of an internecine struggle consuming another civilization. But the struggle in Charlottesville is a struggle within our own civilization, within Trump’s own civilization. It is precisely at moments like this that an American president should speak up directly on behalf of the American creed, on behalf of Americans who reject tribalism and seek pluralism, on behalf of the idea that blood-and-soil nationalism is antithetical to the American idea itself. Trump’s refusal to call out radical white terrorism for what it is, at precisely the moment America needs its leadership to take a unified stand against hatred, marks what might be the lowest moment of his presidency to day.