Hagel Lifts Veil on Major Military Center in Qatar AL UDEID AIR BASE, Qatar - Defense Secretary Chuck Hagel's visit to the advanced air operations center here this week was not just a stop at an important outpost of the United States military. It was also a major step forward for Pentagon transparency. The highly classified American facility, officially called the Combined Air and Space Operations Center, coordinated all of the attack and surveillance missions for the wars in Iraq and Afghanistan - and would be equally critical if an American president decided that only bombs and missiles could halt Iran's nuclear ambitions. It hosts liaison officers from 30 allies in Europe and the Persian Gulf. Until this week, however, its location was carefully guarded by the Pentagon and the Qatari government, out of concerns from both about sensitivities to its presence. In the past, journalists had to sign nondisclosure agreements if they wanted to report from inside the base in the desert outside the capital, Doha. And, when asked, the Pentagon said the operations center was somewhere in Southwest Asia. But on his latest trip to the region, which ended Tuesday, Mr. Hagel lifted the gag rule. Touring the headquarters, usually referred to by its acronym, CAOC (pronounced KAY-ock), Mr. Hagel described the air operations hub as "one of the most impressive facilities we have." Inside the warehouse-size command center, three giant digital maps carried tracking details of every aircraft - civilian and military - in the skies over three vital regions: Syria and its neighbors, the Persian Gulf and Afghanistan. Pressed to explain the rationale for finally acknowledging the air operations center and its location. Pentagon officials said the point of the defense secretary's week of travels was to prove to Persian Gulf partners that the United States would remain engaged in the region - despite budget pressures at home, a rebalance of interests to Asia and the end of the wars in Iraq and Afghanistan. In essence, the American military cannot reassure its allies and deter potential adversaries if it hides what it does, and it helps to show that it can do it from right in the neighborhood. There was no official comment on the disclosure from the Qatari government. But a senior Pentagon official described Mr. Hagel's conversation with his Qatari counterpart, Maj. Gen. Hamad bin Ali al-Attiyah, on the standard diplomatic rules of anonymity. The general noted that Bahrain openly embraces the American Fifth Fleet, and so that tiny nation is known as the focus of efforts to defend waters of the Persian Gulf. According to the Pentagon official, General Attiyah then said that Qatar was proud of its role hosting the command center defending the region's airspace. Defense secretaries always stop at American military installations on their global travels, both to speak with commanders about the mission and to extend the nation's thanks to forward-deployed troops. But the sensitivities of host nations sometimes make it difficult on reporters. For example, on Mr. Hagel's previous trip to the region, in the spring, when he unveiled arms-sales deals worth almost $11 billion, the traveling press boycotted one troop visit because the gulf state said the location could not be identified - even though it routinely appears even in official Pentagon announcements. Officials at the center said the United States and its allies still fly more than four dozen fighter or bomber missions over Afghanistan every day, all coordinated here - although the number of times they drop ordnance in support of troops on the ground is rare as the war winds down. But interest in what is happening on the ground in Afghanistan is undiminished, and the center gathers more than 800 hours of surveillance video over the war zone every day. In a single long workday on a trip whose purpose was essentially to shore up allies, Mr. Hagel was on the ground in Afghanistan - as well as Pakistan, Saudi Arabia and Qatar. It would be difficult to pick four partner nations in a single strategic crescent where the prize is higher - or that have more complicated relations with Washington. In Afghanistan, Mr. Hagel made a conspicuous decision not to meet with its mercurial president, Hamid Karzai, who has refused to sign a bilateral security agreement that was unanimously approved by a council of elders that he himself convened. Mr. Hagel's strategy seemed to be for Mr. Karzai to feel the heat from his own public, which polling shows overwhelmingly supports an enduring, if limited, allied military presence. And in Pakistan, Mr. Hagel and Prime Minister Nawaz Sharif agreed on the dangers of terrorism, but disagreed over how to combat militants operating inside Pakistan. The signals from Saudi Arabia and Qatar were a bit fainter, but no less important. In recent weeks, Saudi Arabia has expressed great anxiety about the interim nuclear deal with Iran as giving far too much in the way of sanctions relief in exchange for far too little in the way of guaranteeing that Tehran can never build a nuclear weapon. And both Saudi Arabia and Qatar have rejected American appeals not to arm rebel militias in Syria, especially those with a more extremist agenda than the moderate Free Syrian Army, which has been Washington's portal into the civil war. A senior Pentagon official said that in his meeting with the Saudi crown prince, Salman bin Abdulaziz al-Saud, Mr. Hagel said "that the United States will continue planning for all options to prevent Iran from attaining a nuclear weapon," according to a senior Pentagon official. In Qatar, Mr. Hagel and his counterpart signed a new Defense Cooperation Agreement that includes joint training and exercises and other unspecified cooperative military actions. That was in the winnings category. But officials said Mr. Hagel and the Qataris ended the meetings with their positions unchanged on how to deal with opposition forces in the complicated and bloody Syrian civil war.