If you watched US President Barack Obama as he delivered his speech at the United Nations last week, in which he outlined his country’s plans to combat and finally defeat the self-ascribed Islamic State, you would have had to admit the man was eloquent and fickle.

No one is gong to quibble with his call to arms against this unimaginably brutal group. “This group,” he thundered from the podium, “has terrorized all who they come across in Iraq and Syria.” Then, after enumerating its “horrific crimes,” from starving minorities to beheading journalists, he added, “No grievance justifies these actions. There can be no reasoning, no negotiation, with this brand of evil.”

Were I present in the General Assembly, I would at that point have applauded, or at least nodded approvingly. Implicit in his speech was deep contextual originality and richness of meaning. But then, in mid-course, he brought up the question of Palestine, where he lost his grip. Though he blandly reiterated the mantra that the US remained committed to a two-state solution, he added, “The situation in Iraq, Syria and Libya should cure anybody of the illusion that the Arab-Israeli conflict is the main source of problems in the region.”

And note his use of the words “cure” and “illusion,” implying that Arab perceptions of the place of Palestine in their modern history are illusory, some kind of ailment that afflicts Arab society for which a cure must be found.

That’s a far cry from that iconic speech that he gave in Cairo in 2009 where he asserted that, next to the fractured dialogue between Islam and the West, Palestine was the most pressing issue in the region.

Reportedly, President Obama departed from tradition by writing much of his speech. He would have done well to rely on speechwriters more astutely informed about the pivotal role that, since the 1920s, the struggle for Palestine has played in shaping the Middle East and triggering its people’s discontents.

American administrations never learn, do they? Or when they do, they choose to learn only those things that reinforce their own biases. Who would forget — certainly not those of us who were around as young teens — the time, for example, when John Foster Dulles, the US Secretary of State, arrived in Lebanon in 1955 on an official visit where gave a speech claiming, “the Palestinian problem will be solved only in time, when a new generation of Palestinians grew up with no attachment to the land?”

Those familiar with modern Arab history know that Palestine has always been sacrosanct in the Arab people’s repertoire of national consciousness, in countries that stretch all the way from the Maghreb (where the sun sets) to the Mashreq (where the sun rises). Indeed, when American President Franklin D. Roosevelt met with Saudi King Abdul Aziz in February 1945 in that pivotal three-day encounter aboard the US Navy cruiser Quincy in the Great Bitter Lake in the Suez Canal — a meeting that served as the foundation for the long-standing relationship between Washington and Riyadh — the issue that dominated the talks was the fate of Palestine.

The fate that later did befall Palestine and its people was seen by Arabs as a stab in the back by the West, and as a grievous wound to the inward preoccupations of their history.

Following the dismemberment of that sad land and the defeat of the Arab armies at the hands of the Zionist movement, military coups followed everywhere — coups that resulted in the transformation of countries in the Levant and the overthrow of the monarchy in Egypt.

The nationalist fervor that characterized the region in the subsequent two decades was a response to the Nakba of 1948. Palestine continued to have a mastering grip on the very marrow of the Arab people’s sensibility to this day.

And it may not have been all about what happened to the Palestinians — the way they were robbed of their home and homeland, of their movable and immovable property, of their name and national selfhood. For Arabs at large, it had to do with the unspeakable: The grafting on the heartland of their world in 1948 of a neo-colonial entity at a time in history when the rest of the Third World was being decolonized.

For Arabs, the advent of Zionism in their world, and the inability of that world’s leaders to stand up to the provocations and taunts of that movement, was a humiliating reminder of how helpless they were, how irrelevant their secular ideologies (from Nasserism to Baathism to Communism) turned out to be. They yearned to take matters into their own hands, to be the determining force in their own destiny, to find a way to the clearing.

At a seminal level of relating to it, every major upheaval in the Arab world, from the fervent call for Arab unity in the 1950s to the so-called Arab Spring in the second decade of this century, was rooted in Palestine. Even the terms “Crusader” and “Crusades,” whose origins date back to 1099, still resonate with Arabs to this day. They remain evocative of a moment and place of immediacy in Arab history.

Just as we speak of black rage as being rooted in black history, when African Americans were brought to the US on slave ships, we in the Arab world also speak of Arab rage as being rooted in the humiliations heaped upon us in Palestine.

President Obama, a man of color (the language suits the moment), should know all that. His observation that Arabs should “cure themselves of the illusion that the Arab-Israeli problem is the main source of problems in the region” is at best fickle, at worst offensive.