Pro-Iraqi forces with their Shia militias have encircled Tikrit, the city which they began assaulting on March 2nd, and are now taking significant casualties. Islamic State (ISIS) fighters holed up in the city are now fighting a battle to the death. If you have read plenty of military history, then you would know how difficult it is to engage in a “last-stand” battle (eg. Battle of Thermopylae, Battle of the Alamo, Battle of Rorke’s Drift). In his annals on the “Art of War”, Sun Tzu would sometimes encourage placing your army in such a scenario. Essentially, when you are backed up against a wall, you will fight better than you have in your entire life. That is why Tikrit will be a bloodbath.
But will Tikrit fall, or will pro-Iraqi forces back off? In order to understand this question, one has to understand the forces fighting. The advancing forces are overwhelmingly Shia, and there is thus among them an intense hatred against ISIS. A death in their ranks will be avenged, whether it be against ISIS fighters or supposed ISIS sympathizers.
Furthermore, there is the concept of martyrdom which is heavily emphasized in Shia Islam. The Iran-Iraq war in the 1980s is a perfect example of this, where Iranian mothers encouraged their sons to go into war and become martyrs. There is also the remembrance of the Battle of Karbala. Many Shias commemorate this day through self-flagellation in order to atone for their ancestors’ sin of not rescuing Imam Ali.
Pro-Iraqi forces will take significant casualties, but they will be accepted. It would not be surprising to see thousands of casualties build up in the coming weeks and months. Furthermore, a victory for the attacking forces would prove devastating for ISIS as it would eliminate 13,000 of their fighters. ISIS fighters are furthermore unlikely to surrenders and will likely fight until death. Tikrit will prove to be an incredibly bloody battle, with an intensity which will reach medieval proportions.