It has been reported that 'the insurgents" are using some "EED" (explosive enhanced device).
Shaped charges have alway been at the business end on man portable anti armor and anti bunker weapons.
Put simply, the explosive in the warhead is shaped like a concave lense, which, when detonated, focuses all it energy mach as a magnifying glass can focus sunlight on one spot.
The US was the first to field such a weapon in WWII with the 2.75" 'Bazooka". This was followed by the odd little "PIAT". literally a spring launched little shaped charge weapon (limited effectiveness.
The next in line were the German Weapons "Panzerschrecht" and "Panzerfaust:. The former was pretty much a duplicate of the "Bazooka" and the latter similar in concept to the US LAAW. Like the 40mm LAAW it was a one shot affair.
Generally the nature of the shaped charge reguirement for a man portable AT weapon dictated a low launch and impact speed (or the shape and focus of the chaped would be destroyed). These earlier weapons (upped to 3.5in in US service to deal with the DPRK T-34's, were limited in range as the propellant was completely exhausted by the time the projectile left the tube
to avoid 'toasting' the launcher.
Then the game changed. TheSoviets set out to make the best Man portable AP weapon in the world, and they did. I must say that I remain mystified as to why we did not just copy the dern thing and have done with other methods.
The Various RPGs were a quantum leap ahead of earlier shaped charged launcher.
A sort of 'squib' launch charge started the missile on its way, but when the missile reached a certain distance from the launcher a small rocket engine in the missile would ignite.
Despite the limitations of space in the missile for propellant. the RPG series was effective an estimated 100 yards minimum additional effective distance over the previous weapons mentioned.
This invention was akin to the introduction of the Longbow(without the necessity for Yeomen who could manage the 100lbs pull of the Yew Longbow.
In theory if one could build a large enough shaped charge weapon, no amored vehicle was safe.
Chobham, reactive and other types of 'spaced' armor decreased the threat .
Now EED's (explosive enhanced device) had increased the effectiveness of the shaped charge weapon simply by increasing the size of the charge and by increasing the strength of the metal liner holding the charges shaped.
Again, not amored vehicle is really safe if the shaped charge is large enough, not even the M1A1 Abrams.
I know little as yet about the workings of these EEDs except reporters are way ahead of themselves in reporting the demise of American Armor in Iraq.
The basic technology to increase the effectiveness of shaped charged weapons seems, as of today's hysterical reviews, as though it may have originated in Iran.
One wonders if this is another advancement of tecnology supplied to Iran in the Iran/Contra affair whose effect was not foreseen.