The French used modafinil in the first Gulf War, and the U.S. Air Force tested the drugs on pilots flying 40-hour sorties during Operation Enduring Freedom in Afghanistan.
Unconfirmed reports say American soldiers took modafinil as they marched into Baghdad in 2003.
Doctors have long "tinkered" with artificially enhancing the brain, and the military spends about $100 million each year on research to find ways to reduce soldiers' need for sleep and still retain cognitive function, according to Moreno.
"The human being is the weakest instrument of warfare," he said. "[Soldiers] must eat, sleep, discern friend from foe and heal when wounded … The first state to build superior fighters will make an enormous leap in the arms race."
Until now, the military has used amphetamines or "go pills" for its pilots, but the side effects of amphetamines can cause problems. Investigators blamed those drugs for a 2002 incident in which American pilots inadvertently killed four Canadian soldiers in Afghanistan.
In studies funded by the Air Force Office of Scientific Research and Cephalon, modafinil has proved to be a better drug.
Scientists treated 16 healthy subjects, depriving them of sleep for 28 hours and then expecting them to sleep from 11 a.m. to 7 p.m. for four days and stay awake through the night. Those on modafinil did far better on cognitive tests than those on a sugar pill. Some could stay awake for more than 90 hours, according to Moreno.
And rather than giving the user a high, it feels as if the user has "just taken a short nap," said Moreno, who has used the drug himself. "It's really fantastic."
But ethicists wonder why performance-enhancing drugs should be so readily available when they have been banned for Olympic athletes.
The military -- sensitive to the fine line between "enhancement" drugs used illegally by athletes and "super drugs" for soldiers -- euphemistically calls modafinil a "performance modification drug," according to Tom Erhard, a former Air Force colonel.
"Human performance modification will become an increasingly evident and problematic part of society, not to mention the military," Erhard, now a senior fellow at the Center for Strategic and Budget Assessments, told ABC News.
"In 10 years, you will be asking yourself about everyone you encounter -- 'I wonder what they're on?' -- because everyone will be on something," he said
Still, Erhard supports military research on performance drugs.
"We are really concerned about what other nations might do," he said. "In Fallujah [Iraq] we ran into insurgents and terrorist jacked up on various substances that enhance performance."
"Other cultures don't have the inhibitions we do and are more apt to look at illegal enhancement," he said.
The civilian battlefield is also rife with controversy over drugs like modafinil, which is increasingly being used as a lifestyle drug.
The Times of London reported last month that increasing numbers of students are using it as the "smart drug" of choice and prefer it to the anti-hyperactivity drug Ritalin. The growing use and acceptability is at the center of a larger debate on scientific advancement.
"We are entering new territory," said Moreno. "Traditional ideological lines break down around this."
Moreno and others worry about the long-term effects of using a drug that curtails sleep.