NEW YORK — The gunmen used silencers on their weapons when they assassinated Assyrian Orthodox priest Youssef Adel outside his home in Baghdad last Saturday. But their message was loud and clear: Iraq’s dwindling Christian minority is the target of a cruel bloodletting.

It may seem insensitive just to single out one group for sympathy in today’s Iraq, but estimates that half Iraq’s Christians have fled speak volumes to the horrors they have suffered since the 2003 U.S.-led invasion.

Father Youssef was the first priest to be killed in Baghdad since the invasion; the second to die in violent circumstances in Iraq in less than a month. The body of Archbishop Paulos Faraj Rahho, one of Iraq’s most senior Chaldean Catholic clerics, was found in a shallow grave on March 13, about two weeks after his abduction in Mosul.

We do not know if Archbishop Paulos, who was elderly and reported to be on medication for heart problems, died from the stress of his abduction or if he was tortured and murdered.

He can be considered lucky. In 2006, Orthodox priest Boulos Iskander was also abducted in Mosul. Even though his family paid a ransom for his release, the group which kidnapped him still beheaded him, and the priest’s arms and legs were also cut off.

Many lay Christians in Iraq complain that radical Muslim groups have given them a choice: convert to Islam, leave, or die. Christian women have been warned to wear headscarves.

Iraq’s Christians are targeted by both radical Sunni and Shi’a. Unlike those Islamic sects, Christians do not have militias or large tribes to protect them. That leaves them particularly vulnerable to kidnappings and ransom demands by criminal gangs, who may pose as Muslim radicals — or by the real radicals who target Christians because of their beliefs.

As a Muslim, I condemn the savagery unleashed on Iraq’s Christians, and not only out of altruism. I defend freedom of worship, but it is imperative to defend the rights of Iraqi Christians (and others such as the Yezidis) because those who target them are sworn enemies of all of us who fall outside their narrow lines of orthodoxy.

Just as elsewhere, minorities in the Arab world have always been the proverbial canaries in the coalmine. Their suffering is a first sign of political ills. My country of birth, Egypt, flourished when its minorities lived well during the first few decades of the last century. Decline set in when they were persecuted — symbolized most poignantly when Gamal Abdel Nasser’s expelled Egyptian Jews in the 1950s.

I opposed the invasion of Iraq and remain as bewildered as many as to the Bush administration’s motivations, and horrified by the disastrous spectacle it has created there. But the invasion did not create the problem of minority rights in the Arab world.

During the last few years of Saddam’s rule, Iraq’s Christians were already feeling hemmed in by his flirtation with Islamic fundamentalism. The plight of Iraqi Christians today is the most fearful example of a growing discomfort their coreligionists are experiencing throughout the Arab world.

Islamist politics has taken root on the grave of Arab nationalism, which was once a safe harbor for both secular Muslim Arabs eager to separate mosque from politics, as well as Christians keen to stress the ethnic over the religious ties that bind. In fact, it was Syrian Christian Michel Aflaq who was the ideological father of Baathism, the secular ideology espoused by Saddam.

Despotism, corruption and the 1967 defeat against Israel dealt Arab nationalism a fatal blow, and cleared the way for the development of political Islam and its hostility to minority rights.

With HAMAS in Gaza and the growing influence of the Muslim Brotherhood in Egypt — and variations on that theme throughout the region —it is a worrying time to be a Christian. Arab Christians today must watch with unease and genuine fear the rise in power and influence of Islamist politics and the subsequent Islamicization it has inspired — even among so-called secular dictators.

Whether it’s al-Qaeda’s murderers in Iraq, or Islamist prejudice in other parts of the Arab world, the defense of minorities in the Arab world must not be left only to the Vatican or Western church leaders. We then encourage the dangerous notion that Arab Christians are somehow alien to the very region which gave birth to their faith (and its rightful affiliation with the other two Abrahamic religions).

Respecting minority rights is of course the ethical thing to do. But it is essential at a time when Muslims in the Arab world increasingly raise their complaints about Islamophobia. It is hypocritical to demand that the West respect its Muslim minorities while minorities in the Arab world are attacked.

And so that quiet murder of Father Youssef has reverberations far beyond the gate of his Baghdad home where he was felled.

Mona Eltahawy is an award-winning New York-based journalist and commentator, and an international lecturer on Arab and Muslim issues.