"The year I've been in charge has been crazy and very, very stressful for the players," Arnold told AFP by phone from Baghdad, shortly before heading to Spain for a pre-tournament training camp.
"Every game basically since I've been here has been a game of life and death."
That might sound extreme, but Iraq were not just left battling to secure qualification right up until the latest possible moment -- their prospects of reaching the finals were also seriously compromised by the war in neighbouring Iran.
Arnold, 62, was appointed in May last year to succeed Spaniard Jesus Casas. At that point, the Lions of Mesopotamia were pushing for direct qualification in Asian Group B behind South Korea and Jordan.
But on Arnold's debut, 10-man Iraq lost to the Koreans. They eventually had to win a two-legged play-off against the United Arab Emirates -– courtesy of a decisive Amir Al-Ammari penalty in the 17th minute of injury time -– to progress to an intercontinental play-off in Mexico in March.
However, at that time, the US and Israeli airstrikes on Iran left many Iraqi players and staff stranded and scrambling to make the long trip.
"The airspace was shut down in Iraq. I couldn't get back into Iraq to get my coaching equipment. The players couldn't get out of Iraq," Arnold recalls, detailing the 26-hour bus trip they took from Baghdad to Amman in Jordan.
"And they got stuck in Jordan for 28 hours because of bombs going off around them and they shut down the airspace.
"When the boys actually got there, it took 68 hours. One of the first meetings and discussions I had with the players was, OK, with everything that's going on in the Middle East, are you going to use that as an excuse or motivation?"
Iraq defeated Bolivia 2-1 in Monterrey, securing a first World Cup appearance since 1986 after an interminable 21-match qualifying campaign.
"The players went through a hell of a lot of stress and a lot of pressure on their shoulders from 46 million people in Iraq to qualify for a World Cup for the first time in 40 years," said Arnold.
"Every one of those games was heartbreak or we survived."
Arnold, who has been splitting his time between Australia and Iraq, insists his team does not lack ability but that his biggest job has been changing mentalities.
"What I've felt in my time here, is that Iraq is a very negative country, because of all the shit that's gone on with the wars over the last 30 years - there's a bit of a negative mentality here, no one likes us, everyone hates us," he says, referring to the Gulf Wars of 1991 and 2003.
This may only be Iraq's second World Cup, but the country has a footballing pedigree -- they won the Asian Cup in 2007 and were semi-finalists in 2015.
"I've never seen a country so obsessed with football. They have public holidays when Barcelona play Real Madrid," says the coach.
Arnold took his native Australia to the 2022 World Cup in Qatar, leading them to the last 16 where they pushed eventual winners Argentina close.
Despite the adulation he has received from Iraqis, he says he felt far greater pressure as coach of the Socceroos.
"I have the greatest respect for people like Didier Deschamps that has stayed and coached his nation for so long.
"The pressure of coaching your own nation is crazy because you don't want to let them down.
"I feel like I'm more of a football coach now with Iraq than with Australia."
Iraq are in a daunting group at this World Cup, starting against Norway in Boston on June 16 before also playing France and Senegal. So what can they realistically achieve?
"We qualified last. If you went through every individual player and every team, and the transfer price of all the players, we would probably be the lowest-ranked at the World Cup," says Arnold, whose contract expires on July 31.
"But it's a World Cup. Anything can happen. And our boys have a great fighting mentality. It's 11 versus 11.
"And if we win our one-versus-one battles, we can shock the world."