BAGHDAD -- As US soldiers fired a hail of bullets, the first suicide bomber sped toward their patrol base. Reaching the checkpoint, the truck exploded, blasting open a path for the second bomber to barrel through and ram his truck into the concrete barrier about 90 feet from the base. The second explosion crumbled walls and parts of a school building, killing nine American troops and injuring 20.
Mourning his fallen comrades yesterday, Lieutenant Colonel Michael Donnelly took comfort in a single detail: The bombers did not detonate their payloads inside the base, located in Sadah, a village near Baqubah, 40 miles northeast of Baghdad.
"It certainly could have been worse," said Donnelly, a US military spokesman, describing Monday's attack, one of the deadliest against US ground forces since the US-led invasion in 2003.
American forces are increasingly exposed to danger and death as they step up their presence in Baghdad and volatile areas such as Anbar and Diyala provinces. Once housed in vast, highly secure bases, many now live in hostile neighborhoods inside isolated combat outposts, the lynchpin of a counterinsurgency plan designed to wrest control of streets and towns from Sunni insurgents and Shi'ite militias.
Military tactical specialists say such combat outposts, where soldiers are expected to interact with area residents and gather intelligence about potential enemies, are the most effective way of preventing car bombs and other attacks in the long term. Paradoxically, this approach is making US soldiers more vulnerable as they rely more than ever before on the Iraqi police and army and the support of the local population for their safety.
Insurgents are starting to take advantage of this exposed presence, staging daring frontal attacks designed to cause heavy casualties, a departure from their trademark hit-and-run and roadside attacks. In a similar coordinated assault on Feb. 19, insurgents attacked a US combat outpost in Tarmiyah about 30 miles north of Baghdad, killing two American soldiers and wounding 17.
"I would refer to them as probing actions to determine vulnerabilities," said retired Colonel Andy Berdy, a former battalion commander in the Army's 101st Airborne Division, referring to the two attacks.
"I think that Al Qaeda insurgents are going after any target that looks 'soft' or 'promising,' wherever those may be," agreed Colonel Jerry Morelock, a former director of the Army's Combat Studies Institute.
Yesterday, the Islamic State of Iraq, an umbrella Sunni insurgent organization said to have been created by Al Qaeda in Iraq, claimed responsibility for the attack in Sadah, located in Diyala province. In a statement, the group claimed it had sent "two knights" to bomb the "Crusader American base."
Diyala, a major flashpoint of Sunni, Shi'ite, and Kurdish tensions, has become the third deadliest area in Iraq for US casualties this year, after Baghdad and Anbar provinces. As militants have fled a 10-week-old security offensive in Baghdad, they have engaged US and Iraqi forces in Diyala, where the US is sending more than 2,000 reinforcements to combat the growing insurgency. At least 56 US soldiers have died in Diyala since November.
"There is a lot of work still to be done in Diyala province," General David Petraeus, the top US commander in Iraq, said in an interview before the attack in Baqubah.
"What you are trying to do is to improve security in neighborhoods. That means you have to get into the neighborhoods," he added.
US soldiers have set up at least seven combat outposts and patrol bases in and around Baqubah, while others are spread throughout the province. The stations, intentionally placed in some of the most dangerous areas to try to deter violence, are erected in homes, schools, police stations, and at government buildings. They are guarded by tall concrete barriers, concertina wire, large bags reinforced by metal and filled with dirt, and machine gun positions on rooftops and in windows.
Military specialists said Army commanders would "harden" the outposts more in response to the attacks.
The US military said yesterday that a Marine was killed Monday during combat operations in Anbar, bringing the American death toll for the day to 11.