The United States in Iraq, population 16,000, is a country within a country. It has a $6 billion budget, its own airline and three hospitals, and imports virtually all of its food. Its central fortress, otherwise known as the Baghdad embassy compound, is nearly as large as Vatican City.

But what seemed like a good idea seven years ago — when plans to construct the embassy and its various outposts were initiated and U.S. interests in Iraq appeared limitless — now increasingly looks like a white elephant of questionable value and staggering expense, critics say.

“The place was a relic before the paint was dry on it,” Sen. Patrick J. Leahy (D-Vt.), who chairs the Appropriations subcommittee on State Department expenditures, said of the 104-acre embassy compound, the largest and most costly U.S. diplomatic mission in the world.

Leahy is awaiting President Obama’s new budget request, due Monday, to see whether the administration shares his views. If not, he said, “I’m not sure Congress is going to go along with it much longer.”

Patrick F. Kennedy, the State Department’s long-serving undersecretary for management, said that the White House has not asked him to shrink the embassy, and he had no indication that the budget would be cut.

Officials in Baghdad and in Washington were already examining whether the mission was “right-sized,” Kennedy said. “We’re now in the fifth or sixth week since transition” following the final departure of U.S. military forces, and “we’re looking at the numbers.” He dismissed a report, posted Tuesday on the New York Times’ Web site, that the embassy was preparing cuts of up to 50 percent.

Until October, when the Obama administration and the government of Prime Minister Nouri al-Maliki failed to agree on conditions for leaving up to 5,000 U.S. troops in Iraq, State Department officials operated on the assumption that the military would assist diplomats with some security and big-ticket items such as transportation and medical evacuation.

When the last U.S. troops departed in December, the State Department was left with a plan formulated under different assumptions and a better U.S. economy.

Even before the troop negotiations failed, “we were having to predict . . . exactly what we would need with no big DOD there,” Kennedy said, referring to the Department of Defense. “I’m not saying I erred on the heavy side — I’m not about to waste money — but I was being very careful” to make sure that both diplomatic and support services, including security, were provided.

“Never having done a change of this magnitude, we had no playbook to guide us,” he said.

Mostly support personnel

The bulk of the 16,000-strong mission consists of support personnel who provide transportation, food, maintenance and security to the embassy compound, consular outposts in Basra and Irbil, and other installations. Most of them are private contractors who also provide security for travel around the country, which is still conducted by air or in convoys.

About 5,000 are assigned to the Office of Security Cooperation-Iraq, including trainers for senior Iraqi police supervisors. All but about 1,000 of that total are support personnel who sustain and protect trainers at various U.S. installations.

State Department contractors fly and maintain the six aircraft, both fixed-wing and helicopters, that make up what is known locally as “Embassy Airlines.” Food convoys from Kuwait are guarded by private security contractors under an inherited military contract.

There are about 2,000 diplomats, intelligence personnel and other U.S. government officials who are assigned what are normal functions in most embassies. But questions have been raised about how those numbers are allocated and about the value of operating in a country where trips beyond secure walls are rare.

Although there are about two dozen public diplomacy specialists, the embassy’s commercial section has only two full-time officials, according to P.J. Dermer, a 30-year military veteran and Mideast expert who served three high-level tours in Iraq. Now a businessman trying to forge links between U.S. and Iraqi businesses, Dermer said the embassy is ill-equipped to assist such efforts.

“It’s not staffed for it. They can’t go outside the walls,” and the embassy “doesn’t have the influence” with Iraqi officials and business leaders, he said.

One of several business leaders who participated in a Commerce Department trip to Iraq in 2010, Dermer described “big fanfare, but absolutely no follow-up. Not one iota. Nothing. I went back several times, I couldn’t get a meeting with anybody in the embassy without incredible effort and begging,” he said. “And once you get in there, there’s absolutely nothing they can do for you.”

“It’s a completely disconnected policy,” Dermer said. “If you want to influence the environment, you should be carrying on like the Chinese, the Japanese, the Dutch” and others in Iraq. “You’d think it would be the last peg in the strategic planning chip” after the military departure, he said. “It’s obvious that it never was.”

Dermer and other businessmen, as well as American diplomats, put some of the blame on the intransigence and incompetence of Iraqi government officials, who have thrown obstacles in the United States’ path.

‘Constantly’ reviewing staff

Kennedy said the size of the embassy’s commercial office is determined by the Commerce Department, which funds its own staff, and not the State Department, although all embassy personnel are under the supervision of Ambassador James Jeffrey, whose Baghdad tour is due to end next month.

The embassy and the State Department, Kennedy said, are looking at overall staffing and are “always seeking to find the right size. That’s something that’s ongoing, constantly.”

The embassy, Kennedy said, is “beginning to get some traction” on plans to “increase the number of local employees and to increase sourcing of goods and services locally.”

But sending a handful of diplomats home would have little effect on the overall size of the mission, Kennedy said. “If you got rid of so many people, you still have a compound with so many linear feet of wall . . . to protect. If you drop three people or 30 people, is the size of the compound going to change? You still need medical capability . . . and medical evacuation capability,” he said. Each plane still requires two pilots.

Leahy said he has asked the State Department for an updated briefing on the embassy’s size.

“I’ve been in embassies all over the world,” he said, “and you come to this place and you’re like: ‘Whoa. Wow.’ All of a sudden you’ve got something so completely out of scale to anything, you have to wonder, what were they thinking when they first built it?”