The war on drugs is fought mainly on the streets. Undercover cops make arrests. Buy busts are their weapon of choice against the dealers.
San Francisco police Sergeant Dave Martinovich is a veteran narcotics officer who knows the drug turf well. Policing it can be difficult.
"Unfortunately there's a lot of people who use a lot of different drugs," he said.
Now the war has evolved to perhaps an even more difficult marketplace with a new set of drugs.
The battles are being fought by federal agents both on the Internet, where the drugs are sold openly, and at airports and post offices where the drugs come in. They're fought by chemists in DEA labs where they try to identify their chemical compounds.
The drugs are sold in small, colorful packages with names like "Wow" and "Purple Haze."
These are synthetic drugs. Most of them are being produced from labs in China, India, and Pakistan. The most popular are the ones that mimic bath salts and marijuana.
Synthetic bath salts are stimulants that affect the central nervous system. Synthetic marijuana is commonly known as "Spice." They're also marketed under other labels like "Mr. Nice Buy" and "Barely Legal."
"We're seeing them a lot at club parties," said Bruce Goldberg. "We're seeing them marketed in packages that are marketed specifically for the young, to our teenagers, and to young adults."
Bruce Goldberg is with the San Francisco office of the Drug Enforcement Administration. He says their research indicates the drugs are extremely dangerous.
"Taking these types of drugs can have a tremendous effect on the development of young people's brains," he said. "The purity, the strength, the side effects are all unknown."
The synthetic drugs are difficult to catch. Many of them are not designated as contraband because they have chemicals that haven't been banned yet by our government.
Once the DEA identifies that chemical through a lab analysis, the agency can then begin the process of outlawing it. But the drug producers are always trying to outsmart the DEA. It's a cat and mouse game.
"This is a way for people in the illegal drug market to try and stay one step ahead of the law, by altering the chemical compound of these synthetic drugs to make new drugs that aren't identified yet," Goldberg said.
But the DEA is making progress.
Last year federal agents won a big victory against synthetic drugs when they cracked an international drug trafficking ring and arrested more than 50 people in the U.S. and abroad. They seized massive quantities of synthetic drugs made in China.