In his weekly audience, the 84-year-old pope reflected on the packed three-day program that saw him travel throughout Iraq last weekend, offering encouragement to persecuted Christians and extending a hand to Shia Muslims.
"After this visit, my soul is filled with gratitude -- gratitude to God and to all those who made it possible," he said, citing political and religious leaders.
These include top Shia cleric Ayatollah Ali al-Sistani, "with whom I had an unforgettable meeting".
He said he heard first-hand of "wounds still open" from the destruction wrought on Iraq's Christian communities, which have been decimated after decades of conflict.
"And at the same time, I saw around me the joy of welcoming Christ's message," he said.
"The Iraqi people have the right to live in peace. They have the right to rediscover the dignity that belongs to them."
He condemned the "monster" of war, adding: "I ask myself, who sells arms to terrorists? Today, who sells them to terrorists?
"They are waging wars in other places as well, in Africa, and it's a question that I want an answer to."
But he noted that Iraqis "are trying hard to rebuild. The Muslims are inviting the Christians to return and together they are restoring churches and mosques. Fraternity is there".