In an otherwise interesting piece on the issue of Mosul and whether we telegraphed our intentions, the author says this about the ability to fight and seize Mosul:
Whatever the rationale behind the U.S. statements, the overall plan to retake Mosul carries serious tactical and strategic risks. These risks exist whether CENTCOM releases a trailer for the campaign or not. Urban combat is costly—even if you win. The United States knows this from its own history in cities such as Hue during the Tet Offensive of the Vietnam War. The Iraqis know it from their history, too, such as the battles for Khorramshahr and Basra during the war with Iran.
I'll ratify the Khorramshahr experience.
But I don't know what the author is talking about when citing Basra.
Basra was the subject of many Iranian offensives in the Iran-Iraq War. But I don't believe the Iranians ever made it closer than 6 miles to the city in the face of stiff Iraqi resistance and many fortifications and obstacles.
So there is no urban warfare experience inside Basra for Iraq to draw from.
UPDATE: This was as close as Iran got to fighting inside Basra:
In January 8, 1987, Karbala Five signaled its beginning when waves of Iranians rushed the Iraqi lines northwest of Khorramshahr. As Rafsanjani predicted, the Iraqis stood their ground and fought. Final victory was not, however, the result. In standing to fight, the Iraqis gunned down the Iranians who stubbornly attacked in the face of crippling losses as they slowly shoved the Iraqis back. By January 22, 1987, the Iranians had advanced to within ten kilometers of Basra, the objective on which Iran pinned her hopes of victory. By the fourth week of the offensive, Iran's attack force was spent and the Iranians dug in to hold their exposed positions at the outskirts of Basra. Iraq's counter-attack called upon all the available reserves and smashed the Iranians to end the offensive for good. Perhaps 20,000 Iranians died in the battle. Iraq's casualties were about half of Iran's. Iraq's performance is notable in that Iraq withstood and won the kind of brutal bloodletting that supposedly only Iran could endure. Observers at the time saw only that Iran had launched yet another in a seemingly endless series of big offensives. They speculated about how many more of these attacks Iraq could endure. Actually, Iran broke at Karbala Five. It would be many months before observers began to wonder what was wrong with Iran when no further attacks were begun, yet it was true that the "Islamic Revolution bled to death in Karbala V."
So there you go.