The Marine colonel is tall and lean. His parents fled Castro's Cuba for U.S. democracy. He talks in measured, confident tones. His expertise is in staff work: making bureaucratic organizations run smoothly.
The Iraqi general is stocky, volatile and sometimes exasperated. He sheds no tears that Saddam Hussein is gone but worries that democracy here will descend into chaos and leave the country vulnerable to attack from Iran. His expertise is in leading troops from the front, and he has the wounds to prove it.
Despite their different temperaments and backgrounds, Marine Col. Robert F. Castellvi and Iraqi Maj. Gen. Tariq abd Wahab Jasim have formed a personal and professional bond around a shared goal: to get the new Iraqi army ready to stand on its own, allowing the Americans to go home.
The relationship between Castellvi and Jasim, and other U.S. and Iraqi officers, is key to what the Americans call the transition phase, with the U.S. pulling back and the Iraqis assuming more responsibility for their security.
Castellvi acts as senior military advisor to Jasim, who commands the 7,000 enlisted men and 700 officers of the 1st Iraqi Army Division, among the most highly rated of the army's 14 divisions.
The partnership will be sorely tested as Marine forces begin to draw down in the sprawling western province of Anbar. A Marine buildup here began in late 2006, months before the Army's infusion of additional forces in Baghdad. Of four extra Marine battalions, three have left and the fourth will follow within weeks, putting increased pressure on the Iraqi army.
The two officers have been ordered to carry out the strategy devised by their superiors in Baghdad: Shift Iraqi army units away from cities and into wide-open areas of Anbar to intercept insurgents moving from the Syrian border toward the cities of Fallouja, Ramadi and even as far as Baghdad.
If the Iraqi army can stop the insurgents, it will hasten the day that more Americans can return home. Iraqi forces already are repositioning; the shift soon will accelerate.
A marine study last year emphasized that the Iraqis needed to strengthen their administrative, supply and communication procedures -- in short, to learn how to get a steady supply of beans, bullets and Band-Aids to their troops.
Jasim concurs. He worries not about the fighting skills of his men but about communications and getting enough ammunition, fuel and weaponry from the Ministry of Defense.
Castellvi, who leads a 45-man advisory group, says the Iraqis are more competent than they think. In many ways, his assignment is to build their confidence level.
Seven days a week, Jasim and Castellvi start off with a lengthy briefing from Jasim's staff on topics such as current and future operations, the amount of fuel available, and how the Iraqi press is covering the war. Castellvi interjects comments sparingly.
During a three-day period in late February, the two were together constantly, planning future moves.
At a Sunday morning briefing, Castellvi made sure to boost Jasim's confidence as photos flashed on a screen showing recent work of Jasim's soldiers in Diyala province: discovering caches of weapons, killing insurgents in firefights and feeding smiling children.
"You should be very proud of your soldiers," Castellvi said.
"Yes," Jasim said, "I am."
Jasim, an old-school general trained under the Soviet top-down model, appeared less happy later. He came close to angrily canceling a fuel convoy because his troops had not informed him in advance of the route. Jasim is a micro-manager, which can be seen as both his strength and his weakness. He wants to change but finds it difficult.
Castellvi explained that the route was the same one that Jasim had approved for other convoys, so in effect, his soldiers were following his leadership. The convoy was allowed to proceed.