Four years ago was a depressing time in global geopolitics. US president Barack Obama was pushing through his nuclear deal with Iran, rewarding the genocidal regime in Tehran with billions of dollars in unfrozen assets, encouraging its continued sponsorship of missile development and terrorism, and endangering America and especially our ally Israel. The deal legitimized Iran’s nuclear program and made the pursuit of weapons legal in just a few years. One of the few rays of light at this dark time was Sen. Lindsey Graham. In constant live speeches and media appearances, he blasted the deal and Iran’s annihilatory rhetoric against Israel. I personally remember attending a small lecture for American Jewish leaders in New York where he told us emphatically that all is not lost. The Senate could undertake maneuvers that could delay the implementation of the deal and the money Iran would get from the United States. Lindsey reassured American Jewry that we were not alone and that we had friends who stood with us against Iran’s promise to destroy Israel.Given that principled stand for freedom and against genocide, I was shocked to hear that Sen. Graham is now blocking Senate consideration of a House resolution recognizing the Armenian Genocide.The House resolution overwhelmingly passed 405-11 (anti-Israel crusader Ilhan Omar voted “present” and did not support the bill) in a long overdue recognition of the historical fact that Turkey massacred as many as 1.5 million Armenians from 1914 to 1923. Turkey denies the genocide and the US has long resisted going on record condemning the episode to avoid offending its NATO ally. When Sen. Bob Menendez asked for consent to pass the resolution, Graham objected.His stunning decision to prevent the Senate from acting came after he participated in a meeting between President Trump and Turkish despot Recep Tayyip Erdogan. In what amounted to a non-explanation, he said, “I just met with President Erdogan and President [Donald] Trump about the problems we face in Syria by the military incursion by Turkey. I do hope that Turkey and Armenia can come together and deal with this problem.” He added that he was objecting “not because of the past but because of the future.”Newsweek quoted Armenian-American novelist Chris Bohjalian, who called Graham’s stance “utterly spineless and despicable,” and political satirist Jeremy Newberger, who said, “When is a genocide not a genocide? When @LindseyGrahamSC meets with Turkey.”I rejected the word “despicable” as utterly unfair. Graham has served with distinction in all his years in public life as one of America’s greatest champions of freedom. So why the sudden change?Graham’s position was all the more shocking given his criticism of the president for withdrawing American troops from Syria and Turkey’s incursion to potentially commit another genocide against the Kurds. It was less than two weeks earlier that Graham said the withdrawal from Turkey and yielding to Erdogan would be Trump’s “worst nightmare” and called the Syria pullout “irresponsible,” a “stain on America’s honor” and the “biggest blunder of his presidency.” He went so far as to introduce legislation to sanction Turkey for its invasion.Erdogan is a despot who arbitrarily imprisons political rivals and journalists and stifles press freedoms. He is a dyed-in-the-wool antisemite who has compared Israel to the Nazis and SS. Graham was one of America’s strongest voices against Erdogan’s growing tyranny. So why suddenly cave to the despot at the expense of the historical record?We in the Jewish community know what it’s like to have to battle despicable Holocaust deniers like David Irving. Would we think that our Armenian brethren are any less pained at America’s refusal to acknowledge the genocide?I understand realpolitik and the reluctance to anger the Turks (the reason Israel has not recognized the Armenian Genocide to its own moral detriment). Nevertheless, I cannot help being disappointed at Graham’s sudden willingness to put politics ahead of his most deep-seated principles and conscience.Former senator John McCain withstood torture for years in a Vietnamese POW camp. He and Graham were famously the closest of friends. McCain set high standards for fighting against tyranny, both as naval aviator and as a senator. So why would Graham, who has been such a champion of freedom and an enemy of despots, not stand up to the Islamist dictator in Turkey who acts contrary to all American values? Human Rights Watch noted, for example, that Turkey is “the world leader in jailing journalists.” It represses other critics and is accused of torturing prisoners.Graham has a strong moral compass. It reached its apogee in 2015 when he said it was “crazy” to give Iran “the pathway to a bomb” and “a missile to deliver it.” He accurately observed that when the ayatollah “says ‘death to Israel,’ he literally means it” and that “when he says ‘death to America,’ he wants to accomplish it.”How could he recognize that it was unconscionable to abandon our Kurdish allies and allow the Turks to march into Syria with the intention of wiping them out and be blind to the injustice of acknowledging the Armenian Genocide? Daniel Larison wrote in The American Conservative, “Graham is cravenly doing the Turkish government’s bidding here... The resolution passed by the House neither ‘sugarcoats’ nor ‘rewrites’ history... Graham is carrying water for genocide denialists. It is an insult to the victims of the genocide and their descendants to block this resolution.”I refuse to believe that Graham would ever be involved in any kind of genocide denial. But his decision to block Senate consideration of the bipartisan House resolution has, for now, delayed a vote. But it did not necessarily prevent one in the future. The Senate must do the right thing and approve the resolution.And Sen. Graham should stand on the right side of history and never betray the moral convictions he has long manifested that has in turn inspired so many Americans.The writer is the author of the forthcoming book Holocaust Holiday: One Family’s Descent into Genocide Memory Hell and is the founder of The World Values Network, which promotes genocide memory in mainstream media.Follow him on Twitter and Instagram @RabbiShmuley.