By Herschel Smith at his The Captain's Journal blog - The Ebb and Flow of IED Warfare: U.S. Lives are at Stake.

Due in part to a failure to listen adequately to Eric Shinseki and Anthony Zinni regarding Iraq war planning, along with premature cessation of conventional operations (bypassing large urban areas leading to costly MOUT later in the war) and halting invocation or implementation of counterinsurgency TTPs, the Iraq campaign has been problematic. In Concerning the Failure of Counterinsurgency in Iraq, I said “we were utterly unprepared for the toll that IEDs would take on U.S. troops, and even after it became obvious that this was a leading tactic of the enemy, we reacted with lethargy.” IEDs became one of the two most effective weapons of the insurgents, specifically because of two reasons: their cheap and ready availability, and the fact that they are a stand-off weapon, something unthinkable for the insurgents 40 or 50 years ago...

For a period of time the U.S. has enjoyed some degree of success in countering the effect of IEDs by jamming the signals from the insurgents to detonate them (sometimes from cell phones). Electronics has been put to good use in Iraq, but in case the reader hasn’t noticed, this enjoyment has diminished recently, and there is an increasing trend again in successful IED attacks apparently because the insurgents are employing electronics against us...