ISTANBUL, Turkey — When Pope Benedict XVI came to Turkey eight years ago, it was in the shadow of a controversial speech he had delivered two months earlier in Regensburg, Germany that set off a firestorm of controversy by citing a Byzantine emperor who linked Muhammad with violence.

Nationalist Muslim protesters in Turkey burned the pope in effigy in protest, triggering widespread fears about possible attacks against the pontiff. In the end, there were no security scares, but the fear was real.

As Pope Francis arrives in Turkey today, there’s no such immediate fire to put out in Christian/Muslim relations. Even so, the security concerns are just as palpable, related more to the broad regional situation and especially the rise of a self-declared Islamic State just across Turkey’s southeastern border in Iraq.

Among other things, the ISIS threat apparently has ruled out a papal visit to the border between Turkey and Iraq to the Christian refugee camps, even though Francis had stated he hoped it’d be a part of the journey.

The on-line Islamic State-propaganda magazine Dabiq has issued threats that put Rome and Francis as targets for extremist hostility. The fourth edition of the publication had St. Peter’s Square on the cover and ISIS spokesman Mohammed al-Adnana stated, “We will conquer your Rome,” and “the Islamic State will remain until its flag flies over Rome.”

Ankara, the country’s capital and first stop in the pope’s three days visit, has been in a tight security clamp-down since Wednesday. According to local reports, over 1,000 police officers will be deployed along the roads that will be used by the pontiff, who will not use the Popemobile because large crowds are not expected.

A local court issued a general search warrant for the routes used by Francis, allowing the police to carry out control procedures in Ankara.

Although no information has so far been revealed over what will be the security measures in Istanbul, a policeman working on Thursday in the area of the Blue Mosque, which Francis will visit on Saturday, told Crux that it will be “less significant than the last time the pope came.”

During emeritus pope Benedict’s visit to the majestic prayer site, more than 6,000 policemen were deployed for barricading the historic center of the city in the hours previous to the visit and a three-car decoy operation was used to diminish the dangers.

By visiting the Blue Mosque in 2006, Benedict XVI became just the second pope to step foot in a Muslim house of worship. John Paul II was the first in 2001, when he visited the Olmayyad Mosque in the center of Damascus, Syria.

Eight years ago, the pope arrived amid intense local backlash. A best-selling book in Turkey at the time was titled Papa’ya suikast (“Attack on the Pope”), and subtitled “Who will kill Benedict XVI in Istanbul?”

In a style worthy of Dan Brown, the 300-page book by Yucel Kaya managed to weave the Turkish Secret Service, the Masonic lodge P2, Mehmet Ali Agca (the Turk who shot Pope John Paul II in 1981), and the Catholic organization Opus Dei into the plot.

The book was part of what, at the time, was described as a rising-tide of anti-Christian propaganda in Turkey that led to the murder of the Rev. Andrea Santoro seven months before Pope Benedict’s visit. Three other Catholic priests were badly beaten in the months leading up to the speech in Regensburg, as were two evangelical pastors.

Since the murder of Catholic Bishop Luigi Padovese, killed in 2010 by his own driver who confessed to the fact, screaming “I have killed Satan,” there haven’t been other reported cases of physical violence against Christians.

The government of President Recep Tayyip Erdoğan, who was the previous Turkish Prime Minister, has taken some steps towards religious freedom, but much is yet to be done.

The right to freedom of belief, the right not to believe in anything, and the right to change one’s belief is protected by the constitution.

In practice, however, those who profess a religion different from the Sunni Islam faith promoted by the government are often discriminated against when looking for a job, applying to school, or running for public office.

Although Pope Francis has enjoyed an amicable coverage from the local mainstream media and is a largely unknown figure in Turkey, the Catholic Church and his office aren’t.

According to American Scott Rank, a veteran freelance religion journalist based in Istanbul, the current situation of religious stability could very well be the calm before the storm.

“Any misstep from the pope could very easily ignite manifestations similar to those we had before Benedict came,” he said.

During a press conference in Rome mid-September, Vatican officials said that no extraordinary security measures will be taken, although the pontiff will have to tread lightly in light of the delicate diplomatic tensions between Turkey and the international coalition fighting ISIS in Syria and Iraq.

Regardless, Francis is still expected to denounce violence done in the name of God and voice his concern for minorities, both Christians and Muslims, being targeted by the extremist group.