The U.S. military has assembled the most sophisticated fighting arsenal in the world with satellite-guided weapons and unmanned aerial vehicles that shoot Hellfire missiles. But as billions of dollars have poured into the technology for futuristic warfare, the government has fallen behind on more mundane needs -- such as bullets.

The protracted conflicts in Iraq and Afghanistan and heightened combat training with live ammunition have left the military short of small-caliber bullets. To offset the squeeze, the Army is taking unusual stopgap measures such as buying ammunition from Britain and Israel. It is also working to increase domestic production.

"The big complex programs don't do any good if there aren't bullets for the rifles," said Marcus Corbin, a senior analyst at the Center for Defense Information, a research group based in the District.

Shortages in basic battlefield gear struck soon after the start of the Iraq war, when combat forces outfitted in high-tech uniforms ran short of body armor and armored Humvees. The tight supplies of bullets reflect a shutdown of factories in recent years and the unexpected level of resistance in Iraq, industry analysts said. The Army relies on one plant for its small-caliber ammunition, sharply limiting its options.

The Army estimates that it will need 1.5 billion rounds of small ammunition this year for M-16s and other rifles, triple the amount produced in 2001. The primary U.S. military supplier is the Lake City Army Ammunition Plant, a government-owned facility run by Alliant Techsystems Inc. It will manufacture 1.2 billion rounds this year. "To fill that gap, we had to do some things rather quickly," said Brig. Gen. Paul Izzo, the Army's program executive officer for ammunition.

The military has a stockpile of 1 billion rounds but resists dipping into it except for extraordinary emergencies. "We have a good-sized stockpile" that we keep as "our trump card," Izzo said.

Alliant aims to boost production to 1.5 billion rounds a year, but it is not expected to reach that target for another year. In the meantime, the Army has turned to alternate suppliers. In June, it bought about 130 million rounds from Britain's stockpile. In December, it awarded contracts to Israeli Military Industries Ltd., based in Ramat Hasharon, and Winchester Ammunition, a unit of Conn.-based Olin Corp., to produce 70 million rounds each of 5.56mm and 7.62mm ammunition.

The military will begin moving away from those temporary suppliers next year when it expects to hire a second small ammunition maker to provide 300 million rounds a year on a long-term basis to supplement output at the Lake City plant in Independence, Mo. Alliant is expected to face competition for the contract from Falls Church-based General Dynamics, which already makes large-caliber ammunition.

A second supplier will give the military the ability to quickly accelerate production if needed, Izzo said. "I am responsible for making sure we have an industrial base that is flexible and responsive," he said.

U.S. bullet production has dwindled to just the Lake City plant from five factories that turned out small ammunition during the Vietnam War. "In essence the Army underestimated what its future ammunition needs might be," said Loren B. Thompson, defense consultant for the Lexington Institute, an Arlington think tank.

The military had only one maker of the protective inserts for interceptor body armor. When shortages appeared during the Iraq war, the government accelerated production and now has seven suppliers turning out the gear. Only one factory produces armored Humvees, but output has risen sharply. The number of armored Humvees produced has reached about 350 a month, up from about 60 a month last year. Production is expected to reach 450 a month by the end of the year.

The Army estimates that it consumes about 5.5 million rounds of ammunition in Iraq and Afghanistan each month. About 72 million rounds have been used in Iraq. After the Sept. 11, 2001, terrorist attacks, the military began requiring that soldiers conduct live-fire training twice a year, instead of once, consuming about a 100 million rounds a month. The other services, Navy and Air Force, use about 200 million to 250 million rounds a year.

Alliant Techsystems, based in Edina, Minn., has tripled the workforce at the Lake City bullet plant in the past four years to 1,950 workers, from about 650, and is still hiring. The company pulled machines out of storage and spent millions updating the technology to reach production of 1.2 billion rounds a year, up from 350 million in 2000, company spokesman D. Bryce Hallowell said.

Alliant's 10-year contract to run the facility was expected to generate $100 million a year but has leapt to more than $300 million, Hallowell said.

The Army's use of an Israeli company for ammunition supplies has raised concerns among some in Congress. Insurgents in Iraq could use the Israeli purchases as a recruiting tool, said Rep. Neil Abercrombie (D-Hawaii), a member of the House Armed Services Committee. "It would be utilized by those who wish us ill," Abercrombie said. "To me it seems a very serious issue."

Abercrombie said he was also concerned that the military should not depend on foreign suppliers to address critical war needs. "We need to keep the manufacturing base here and if that costs a little more money, so what?" he said. "If defense is worth having, it's worth paying for."

The Army said it has complied with "Buy America" regulations and that Israeli Military Industries was one of only two providers available. Industry officials acknowledge that the military's options are limited.

Israeli Military Industries said the ammunition will be manufactured in Israel but the raw materials, including propellants, projectiles and primers, come from U.S. sources. "We're there to help as long as we can," said Michael Davison Jr., president of the company's U.S. operations. "It's obviously something very important that the U.S. get the assistance it needs from its friends and allies, and this is a situation in which IMI can do that."

Other U.S. commercial ammunition makers could help fill the gap but cannot break existing contracts with private sector clients or foreign militaries, said Richard Palaschak, director of operations for the Munitions Industrial Base Task Force, a trade association. "There is not a lot of surge capability . . . within the U.S. industrial base," Palaschak said. "So when you get into a situation where [demand has increased] it was clear they had to do some extraordinary things to satisfy the requirements."

Some in Congress are concerned that the Army could be overpaying for the ammunition. The Army has refused to disclose the size of the contracts with Winchester or Israeli Military Industries but acknowledges they are paying a premium of 15 to 20 percent that it attributes to start-up costs, testing and the lower production rate.

"With that kind of cost differential, did we really need" this ammunition immediately, given the Army's stockpile, asked Rep. Curt Weldon (R-Pa.), a member of the House Armed Services Committee. Weldon estimated that the government is paying a significantly higher premium on the bullets.

"If you have to scramble to bring up capacity, then you're likely to pay a premium," said Christopher Hellman, director of the Project on Military Spending Oversight at the Center for Arms Control and Non-Proliferation. "Again it calls for more long-term attention to the basics before spending on super complex programs for the future."

Alliant Techsystems Inc. runs the U.S. military's primary ammunition plant. It will manufacture 1.2 billion rounds this year.