Demonstrators attend a torch-bearing march marking the anniversary of the 1915 mass killings of Armenians in the Ottoman Empire, in

During the 2008 campaign, Barack Obama could not have been clearer about what he thought of the mass killings of Armenians at the hands of Ottoman Turks in 1915.

“My firmly held conviction (is) that the Armenian Genocide is not an allegation, a personal opinion, or a point of view, but rather a widely documented fact supported by an overwhelming body of historical evidence,” he said in a statement. “The facts are undeniable,” Obama wrote. “As President I will recognize the Armenian Genocide.“

Once in office, though? Not so much. Not at all, in fact.

President Obama on Thursday called the slaughter “one of the worst atrocities of the 20th century.” But for the sixth straight year, he did not use the word “genocide” — a move that Armenians would have cheered but would also have risked profoundly angering Turkey, a crucial NATO ally.

“I have consistently stated my own view of what occurred in 1915, and my view has not changed,” Obama said in his 2014 statement. “A full, frank, and just acknowledgement of the facts is in all of our interests.

“Peoples and nations grow stronger, and build a foundation for a more just and tolerant future, by acknowledging and reckoning with painful elements of the past,” the president added. “We continue to learn this lesson in the United States, as we strive to reconcile some of the darkest moments in our own history.”

The issue highlights the chasm between the demands of domestic politics — magnified by a presidential campaign — and those of foreign policy. A better-known version is the aspirant to the White House who promises on the trail to take a hard line on China but bends in the face of managing what is one of the most complex and important American relationships in the world.

As a senator, Obama co-sponsored a resolution calling for the use of the term “genocide” when discussing the Armenian tragedy. A similar proposal cleared the Senate Foreign Relations Committee on April 10 by a 12-5 vote. The only member of the panel not to vote was potential 2016 Republican presidential hopeful Rand Paul.

Turkey fiercely disputes the genocide charge and has warned that formal U.S. steps to use the term will hamper relations. Turkey’s then-ambassador to Washington, Namik Tan, sharply criticized a similar statement from Obama in 2011, taking to Twitter to denounce it as inaccurate, flawed and one-sided.

And Turkish Prime Minister Recep Tayyip Erdogan issued a statement this week declaring that “using the events of 1915 as an excuse for hostility against Turkey and turning this issue into a matter of political conflict is inadmissible.”

“It is indisputable that the last years of the Ottoman Empire were a difficult period, full of suffering for Turkish, Kurdish, Arab, Armenian and millions of other Ottoman citizens, regardless of their religion or ethnic origin,” said Erdogan, who called for a scholarly analysis of the events 99 years ago.

Obama’s statement drew a sharp rebuke from Armenian National Committee of America Executive Director Aram Hamparian, who deplored the “sad spectacle” of Obama bowing to Turkey’s “gag rule.”

“President Obama continues to outsource his policy on the Armenian Genocide, effectively granting Turkey a veto over America’s response to this crime against humanity,” Hamparian said.

Twenty-two countries have recognized the events of 1915 as genocide, and 42 U.S. states have done so as well, either by legislation or proclamation. Congressional resolutions aimed at doing the same at the national level have never become law. Successive presidents have objected on grounds that doing so risks angering Turkey.