For many people, Iraq has become a byword for danger and instability. For this reason, Pope Francis's predecessor, Pope Benedict XVI, said the pontiff's Iraq trip was "important but dangerous".
The Pope's incredible, 4,500-kilometre trip across Iraq, passing through five provinces and several cities, was no doubt a challenge for his security team.
The memory of the May 13, 1981 assassination attempt on Pope John Paul II would have been fresh in the minds of Pope Francis’s personal security detail.
For the Iraqis, the memory of UN Special Representative Sergio Vieira de Mello's death in 2003 would also have been a haunting one. To date, de Mello is the highest profile victim of terrorism in Iraq.
Although the security guards can take pride in a job well done, the failure of ISIS to launch even a symbolic attack points to the group’s astonishing decline.
As recently as January, Iraq’s security forces were coming under attack in the countryside west of Mosul. But compared with past incidents, current ISIS activity is sporadic and attacks are usually small.
This allowed the Iraqi security forces to cordon off Church Square in Mosul, where the Pope delivered his historic call for peace.
The absence of even a symbolic attack during the papal visit does not signal some newfound respect for the Pope among the ranks of ISIS.
As far back as 2015, ISIS propaganda magazine Dabiq showed an image of Vatican City's St Peter's Square on its cover, with the terrorist group's black flag flying aloft.
ISIS had almost four months to plan something, following the Vatican’s announcement of the visit in December last year.
In the past, this would have been more than enough time.
During the rise of the group in Iraq in late 2013, the Institute for the Study of War reported that the forerunner of ISIS was conducting synchronised attacks across Iraq on a monthly basis. At times it detonated more than 10 car bombs in different cities at the same time.
ISIS in decline?
“I was a bit surprised they didn’t do anything but, then again, they’ve done little since November, so it fit into the pattern,” said Joel Wing, an analyst in the US who has been tracking violence levels in Iraq since 2008.
“It might be a lull before their annual spring offensive. It might be because they’re regrouping after their recent leadership losses.”
“Either way this is the fewest attacks since 2003,” he says, referring to overall terrorist violence.
Alex Almeida, an analyst with Horizon Client Access, agrees that the group has been in long-term decline.
“I was a bit worried they would pull off a symbolic, low-capability attack like a bomb in a trashcan or backpack bombing outside the stadium in Erbil, or a lone gunman shooting up a crowd or hotel,” he said.
Mr Almeida said ISIS in its current form is struggling to co-ordinate nationally, as it did successfully in the past.
"They really are struggling to keep up even a low-level pattern of attacks right now. It increasingly feels like ISIS in Iraq is disaggregating into a bunch of separate local micro-insurgencies, remaining cells in north Diyala and rural Kirkuk," he said.
“The underlying drumbeat of attacks that provided a sort of background ‘critical mass’ to the insurgency feels like it’s mostly gone.”
In other words, ISIS has not only lost men and resources, but has also lost almost all of its support among Sunni communities in Iraq. That base of support is the essence of what an insurgency is, an armed movement depending on a degree of local co-operation.
The Iraqi security forces now have a celebrated counter-intelligence branch known as the Falcons and an elite, US-trained force known as the Counter Terrorism Service. Thousands of other soldiers and police were also able to control public movement in areas the Pope visited.
But hundreds of thousands of Iraqi soldiers on regular operations could not stop ISIS attacks in the past.
"The preparations on the ground and from the sky made it very difficult for anyone to launch attacks, big or small, or even infiltrate the areas the Pope visited," a Ministry of Interior security source, who wished to remain anonymous, told The National.
"There were many security cordons on the ground in addition to the full lockdown that helped us restrict individuals' movement, and there were drones and helicopters hovering overhead in all areas," he said.
“To carry out any attack, there should be a group of about five or more to offer logistical support or cover, who can move freely. So anyone, whether ISIS or militias, realised that conditions weren’t perfect.”
The security source said he was surprised the group was silent on the papal visit.
“To be honest, we don’t know why ISIS didn’t issue a statement, but what I can say is that ISIS today is not the one we saw more than six years ago,” he says.
“Not only has their military capability been heavily degraded, but also their presence on social media and their ability to share materials, whether visual or text.”
But the security officer said that this was no reason for Iraqi forces to drop their guard.
“Maybe we can see something on that in the near future,” he said.