Unlike the film, The Bridges of Madison County, the bombed bridges of Baghdad are not a quaint romantic tale, but a warning sign of potential disaster for U.S. forces in Iraq.  The ongoing attacks on bridges in and around Baghdad creates significant risks and logistical obstacles for U.S. forces in Iraq.  In my opinion these attacks are part of deliberate strategy to create ambush chokepoints, degrade the capability of U.S. Quick Reaction Forces, and enhance the ability of insurgent forces to cut the U.S. lines of communication.

Juan Cole summarizes the latest activity:

Guerrillas blew up another bridge in Iraq on Monday, this time over the Euphrates in Diyala province.
Its destruction will make drivers from northeastern Diyala who want to
go to Baghdad take a route through Baquba, among the more violent
cities in Iraq. Guerrillas are attempting to cause Iraqi society and
government to collapse by hitting the infrastructure, and the bridge
demolitions are part of that strategy. Late on Sunday, an overpass leading to a bridge south of Baghdad was destroyed, and 3 American soldiers were killed and 6 wounded.

These attacks continue a trend that started in April, with the attack on the Sarafiya Bridge in central Baghdad (see U.S. Policy in the Drink).  The loss of these bridges represent more than increased inconvenience for commuters and travelers.

Traffic will be re-routed, which means there will be more traffic in a concentrated area.  This is a boon for insurgents who can in turn concentrate their limited resources and simplify their planning for successful attacks.  It also creates logistical nightmares for the United States forces.  Most of the basic necessities required to sustain U.S. forces in Iraq are carried in truck convoys.  The destruction of these bridges will further increase the transportation time for drivers and the maintenance requirements just to keep the vehicles on the road.

Beyond the inconvenience factor, we must recognize that the destruction of bridges can produce the defacto isolation of U.S. outposts and bases.  If a U.S. unit is attacked and requires reinforcements, the loss of these bridges increase the difficulty of the U.S. Quick Reaction Force reaching the scene in a timely manner.  Moreover, with fewer alternate routes available, insurgents can anticipate where to hit a responding American force.  In fact, an attack on an outpost could be a feint intended to provoke a U.S. reaction and give the insurgents the opportunity to ambush the inbound soldiers.

It is incumbent on U.S. commanders to boost security around the bridges.  But that is a manpower issue.  If you do not have enough troops in country then you must divert troops from patrolling streets to sitting on a bridge and guarding its perimeter.  The tactical job of protecting a bridge is fairly simple and straightforward–you need people with guns.  But we do not have enough troops in Iraq to carry out the various missions required to make the surge work.  The systematic destruction of bridges in and around Baghdad are the early warning signs that the mission for our soldiers in Iraq is going to get tougher and more deadly.