Modern organisations are more cautious about issuing powerful substances, but soldiers have already sought to enhance their own performance with less controversial dietary supplements.
Creatine is taken by many athletes to boost their strength and increase muscle mass.
A survey found that just over a third of US Army Rangers were taking creatine or other dietary supplements.
The CNAS report says if such supplements are found to be safe and effective, they should be used more widely and in a controlled manner.
The so-called 'smart drugs' are supposed to sharpen mental performance.
Recent research has focused on Modafinil, which has become popular with students to help them concentrate and counteract the effects of sleep deprivation.
A study by the US Army Aeromedical Research Laboratory suggested Modafinil “shows promise as an enhancement agent,” and the Ministry of Defence (MOD) has commissioned research into the drug.
Modafinil has not been found to actually boost the intelligence of users but a study with chess players found that after taking the drug they spent longer analysing choices and made better moves, increasing their number of wins by up to 15%.