CNN reports ISIS is attempting to take the government complex in Ramadi.

ISIS will fail. This, even more than Kobani, will be known as the  “high water mark” of ISIS. Some may recall this phrase from the history of the U.S. Civil War, of Longstreet’s assault into the Union lines, at the Battle of Gettysburg, on July 3, 1863. This is of that magnitude.

The considerations that form this estimate are as follows:

• All eyes are upon the defenders. They know they will be branded as heros or cowards. In other words, the same “search for significance” which has been discovered to motivate the influx of ISIS recruits is now within the grasp of the defenders.
• To the Iraqis, the asset is worth bending the rules of  air support that minimize civilian casualties.
• The close proximity of official Iraqi  forces facilitates deployment of U.S. ground personnel for precision targeting.
• An ISIS all-out assault has been repulsed. If the LA Times paywall doesn’t stop you, it’s here. For those who rely on open source intelligence, a successful repulse illuminates a ground situation that may be murky even to the participants. ISIS didn’t get it the first time.
• A development of the Vietnam War was a kind of  strongpoint called a “firebase”, which delivered regional artillery support on demand. During U.S. involvement in Vietnam, the North Vietnamese did not succeed in overrunning a single firebase, although some were evacuated for tactical reasons. Although Ramadi is not a firebase, U.S. advisers have a wealth of experience defending similar strongpoints.

A rule-of-thumb for military engagement is that the attacking force must have 3 to 1 force superiority over the defender. But this assumes the forces are organized as conventional forces, with similar discipline, training, and motivation. In this case, it is a question-mark, a wild card. But one French ISIS fighter cites free hair shampoo as a motivation. Although Iraqis in general may lack better reasons,  those defending Ramadi have one: to live or to die.