What is particularly troubling to the military is that the enemy was able to penetrate the Mine Resistant Ambush Protected vehicle, whose V-shaped hull disperses a blast away from the troops inside.
A military source said in an interview that the July 8 bomb likely was a huge fertilizer-based homemade device hidden in a culvert close to where the vehicle passed. An enemy tactic is to place a bomb underneath or alongside a road and detonate it with a remote electronic signal, such as from a cellphone.
The command in Kabul is generally tight-lipped about how the Taliban, al Qaeda and other insurgents use homemade bombs.
“It’s hard to discuss our estimates of the size of the IED [improvised explosive device] or other tactics used by the insurgents in public without giving the enemy valuable information, but I can say that our investigation leads us to believe the IED was considerably larger than the average IED used against mounted patrols,” said James Graybeal, a command spokesman in Afghanistan.
The Pentagon’s top counter-IED official said the enemy is constantly changing its tactics.
“As in any conflict, there is a continual evolution of tactics, and the IED fight is no different,” said ArmyLt. Gen. Michael Barbero, who heads the Pentagon’s Joint Improvised Explosive Device Defeat Organization. “We know that hardening vehicles alone is not a solution to the IED threat, and [my group] deploys and continually improves an array of capabilities to defeat attacks on mounted patrols.”
Rep. Duncan Hunter, California Republican and member of the House Armed Services Committee, told The Washington Times that the insurgents “are building bigger bombs.”
“You can’t build a vehicle larger than the explosives they can pack if they have 48 hours or 72 hours or a week to pack explosives on the ground,” Mr. Hunter said. “They can blow up anything.”
He added: “This is just another example. If you’re not going to catch the bad guys putting these things in, they’re simply going to keep killing Americans. There’s nothing we can build, through all of our power and industrial strength, that can respond to them simply increasing the amount of explosives used. There’s no way to stop this if you don’t catch the guys before this happens.”
One of the main precursors for homemade bombs is the fertilizer ammonium nitrate that is produced in Pakistan and smuggled to the Taliban for making bombs. The U.S. has expressed frustration with Pakistan’s inability to stop the flow of ammonium nitrate into Afghanistan.
Gen. Barbero said his organization is working with other agencies, including the Commerce and Treasury departments, to stop U.S. companies from trading with IED-connected entities and to place sanctions on those involved in the bomb trade.
“Through coordinated efforts and strong partnership across the U.S. government with our international partners, we are going after these nefarious actors and effectively countering the networks that use IEDs,” he said.
The Joint Improvised Explosive Device Defeat Organization’s latest strategic report states: “Bomb makers will take advantage of available technology and innovate in response to countermeasures — weapons will be more lethal and harder to detect and defeat.”