Marijuana is an addictive, gateway drug. It significantly impairs bodily and mental functions, and its use is related to increased violence. These are facts.

Yet proponents of legalizing the drug studiously deny or downplay the well-documented dark side of marijuana trafficking and use. Instead, they promise benefits ranging from reduced crime to additional tax revenue.

Marijuana advocates have had some success in arguing that marijuana is a “soft” drug, similar to alcohol, and fundamentally different from “hard” drugs like cocaine or heroin. To equate alcohol with marijuana, however, is both uninformed and misleading. Their similarities run only skin deep.

A glass of wine with dinner, for example, has been shown to actually improve health. Not so with marijuana. Though it may have some palliative effects, marijuana has no known general healthful properties.

Instead, clinical studies reveal that long-term, moderate consumption of the drug impairs short-term memory, slows reaction time, increases the risk of heart attack, and can result in birth defects, strokes, and damage to the respiratory system and brain.

Lacking curative or preventive powers, marijuana — unlike alcohol — is usually consumed to the point of intoxication. Prolonged use has a negative effect on cognitive ability that persists beyond the period of intoxication.

What about addiction? Legalization advocates note that alcohol and tobacco are addictive, yet legal. Yes, but marijuana is more likely to cause addiction. One study found that more than 30 percent of adults who used marijuana in the course of a year became dependent on it, exhibiting compulsive behavior and signs of withdrawal.

But think of the benefits to society, pot proponents then argue. Legalizing marijuana would slash drug-related crime, they assert. Yet if and when states legalize marijuana, local demand will increase. Meanwhile, some reputable growers, manufacturers, and retailers will refuse to produce or distribute the drug because of standing federal laws and the tort liability that attend to such a dangerous product. The vacuum will be filled by illegal drug cartels and a black or gray market.

Furthermore, the National Research Council has concluded that the “long-term use of marijuana may alter the nervous system in ways that do promote violence.” No place serves as a better example than Amsterdam. Though often touted as a well-functioning city with a relaxed attitude toward drugs, Amsterdam is also one of the most violent cities in Europe. In California, as well, the areas around cannabis clubs have experienced exponential increases in crime rates.

Pot pushers also offer pie-in-the-sky economic arguments on behalf of their cause. Taxes collected from marijuana sales will easily outweigh the social costs of legalization, they say.

In encouraging Californians to vote for the Regulate, Control and Tax Cannabis Act of 2010, the National Organization for the Reform of Marijuana Laws (NORML) predicted a billion-dollar windfall for the state in tax revenues and enforcement savings. A RAND Corporation study subsequently found these projections were riddled with unfounded assumptions. To date, no realistic cost-benefit analysis has been done, yet proponents keep repeating these groundless claims.

Finally, regardless of state law, marijuana remains illegal under federal laws, which states have no authority to allow their citizens to contravene.

Legalizing marijuana is not the answer. Rather, sound national drug policy includes international cooperation, research, strengthened law enforcement, treatment, and prevention and education. When President Ronald Reagan adopted a similar strategy, illegal drug use by young adults dropped by more than 50 percent.

Thus, the best option going forward is for states to commit to a comprehensive, unified approach aimed at preventing illegal drug use and reducing the number of drug users.

No state will likely be allowed to legalize marijuana on its own due to negative cross-state spillover effects. Yet even if a state could do so, legalizing marijuana would serve little purpose other than to worsen the drug problem.

Charles “Cully” Stimson is a senior legal fellow at The Heritage Foundation.