How to Defeat an Urban Phalanx

How to Defeat an Urban Phalanx.   In many ways urban defense is similar to classical warfare's phalanx (a wall of spears -- here is some more information of the use of Phalanx tactics across history).  Both are relatively armored (instead of armor -- urban defense uses houses and rubble), both move slowly if at all, both are relatively immune to the effects of airpower (the spears of an ancient phalanx blocked arrows relatively effectively), and both are extremely resistant to frontal attack by mobile forces.  These parallels provide an interesting way to look at the battle for Baghdad.  Here are the tactics that mobile forces have used in the past to defeat phalanxes (and a little analysis as to whether they are likely to succeed):

• Envelopment.  The easiest way to destroy a phalanx is to attack it from the rear.  This was attempted at the battle of Arbela by extremely mobile Persian cavalry against the Macedonian phalanx.  These attacks were blunted by mobile Macedonian cavalry which guarded the flanks allowed the phalanx to advance unmolested.  In the case of Baghdad, a ground flanking maneuver is likely not to work.  The urban phalanx is formed very much like a British infantry square and a result it doesn't provide a ground flank (in truth it is a circular phalanx).  The only method of potential envelopment is vertical (airpower).  However, the potential for massive collateral damage and its relative inefficiency argues against this.
  
• Force it to break apart via an advance over rough terrain.  The battle of Pydna is an example of this.  The Macedonian phalanx advance over broken and rough terrain.  As a result, holes opened in the formations.  These holes were exploited by more flexible Roman formations to destroy the phalanx.  Given that the armor of urban warfare is the city itself, and therefore fixed, it is unlikely that Iraqi forces will be forced onto ground that is unfavorable to their style of warfare.  Destruction of the city in order to force gaps that can be exploited is ineffective.  As shown in destruction of the cityscape in Stalingrad, rubble is easier to defend than an intact city.
  
• Puncture it with armored forces.  The classic example of this is the Persian use of scythed chariots (remember Ben Hur) against the Macedonian phalanx in the battle of Arbela.  The defensive move Macedonians was to open gaps in the line to enable the chariots to pass through unmolested.  Once through the lines the chariots were enveloped and overwhelmed by lightly armed forces.  To a certain extent, US armored forces are using the broad highways into Baghdad to break apart the city (the recent seizure of the city center is an example).  While this is impressive, it is also dangerous due to the likely difficulty supplying and supporting these troops once they enter the city center.  Additionally, if the escape route is effectively blocked, there is the possibility of them being overrun from a diffuse multiple flank attack.
  
• Grind it down.  Alexander used this tactic against the isolated Greek phalanx left behind at the battle of Grancius and the Theban Sacred band at Chaeronia.  This is the most direct tactic and has been used against phalanx formations across history.  This is the last resort for allied forces.
  
• Trick it into attacking.  This was used most famously by the Norman knights against the Saxon infantry phalanx at the battle of Hastings.  The Normans found that if they attacked the shield wall and retreated, much of the phalanx would break off and chase the Norman knights.  Once exposed, the Norman knights were able to kill the attacking infantry in detail.  The other classic form of this tactic was the battle of Cannae, where Hannibal faked the retreat of his center (while keep the wings heavy and in position) to lure 70,000 Roman legionnaires to their death.  To a certain extent we used this in the Battle for Saddam International airport.  This may also be the tactic behind the plunge into the city center and our other recent forrays into the city.  However, to really work, you have to make the enemy believe you are in general retreat.  I don't think US planners have the stomach for it, despite its potential effectiveness.  If we did do it, we could trick 10-25,000 Iraqi soldiers out into the plains south of Baghdad where they could be killed en masse.  This is turn could create an opportunity for a coup de main of Baghdad.

To sum it up, any or all of these tactics may be used to some effect.