The Obama administration’s decision not to challenge the legalization of recreational marijuana use in two states is not an abdication of its responsibility to uphold federal narcotics laws, a senior Justice Department official told a US Senate subcommittee Tuesday.

Deputy Attorney General James Cole told members of the Senate Judiciary Committee that federal prosecutors and agents are prepared to focus aggressive efforts on interstate and national enforcement of marijuana trafficking laws.

“We are not giving immunity. We are not giving a free pass. We are not abdicating our responsibility,” Mr. Cole testified.

He spoke two weeks after the administration announced that it would not seek to challenge or otherwise undercut voter initiatives passed in Washington State and Colorado last November that legalized the possession and use of personal amounts of marijuana.

Currently, 21 states and the District of Columbia have laws permitting the use of marijuana for medical purposes. Six of those laws were enacted this year.

Only Colorado and Washington have gone the extra step to decriminalize recreational use of personal amounts of marijuana.

Charles Grassley (R) of Iowa objected to the Justice Department’s posture. “These laws flatly contradict federal law,” he said. “Some experts fear they will create a Big Marijuana industry, including a ‘Starbucks of Marijuana,’ that will damage public health.”

“These policies do not seem compatible with the responsibility Justice Department officials have to faithfully discharge their duties,” he said. “Prosecutorial discretion is one thing. But giving the green light to an entire industry predicated on breaking federal law is another.”

Cole said federal officials would aggressively enforce federal drug laws when the illicit conduct implicated one of eight enforcement priorities embraced by the Obama administration.

The priorities include preventing distribution to minors, preventing revenue from the sale of “legal” marijuana from being diverted to illegal drug traffickers, and preventing smuggling of “legal” marijuana to other states where it remains illegal.

He said other priorities include preventing drugged driving, preventing violence and the use of firearms in the “legal” marijuana trade, and preventing the growing of marijuana on public lands.

Cole said that outside these defined federal priorities, Justice Department officials would rely on state and local authorities to enforce their own marijuana laws.

Grassley said the new marijuana enforcement policy was another example of the Obama administration ignoring federal laws that it considers inconvenient or doesn’t like. He cited the administration’s lax enforcement of immigration statutes and failure to abide by deadlines in the health-care reform law.

“What’s really striking in this case is that the Department of Justice is so quick to challenge state laws when it doesn’t like or want to enforce them,” Grassley said. “States that change their voting laws to require an ID? See you in court. States that try to secure their borders when the federal government won’t? Expect a lawsuit. But if some folks want to start an industry dedicated to breaking federal law? Well, then the Department’s position is to wait and see how it all works out.”

Also testifying at the hearing was King County Sheriff John Urquhart, the chief law enforcement officer in Seattle.

The sheriff said he has 37 years experience as a law officer, 12 of them investigating narcotics crimes. “My experience shows me the war on drugs has been a failure,” he said.

Sheriff Urquhart said he was a strong supporter of the marijuana ballot initiative and believes it will help divert drug proceeds from criminals in a way that can be regulated and lead to better enforcement.

The sheriff told the senators that during a short walk from his hotel to a restaurant in downtown Washington, D.C. he and a colleague watched and listened as a small-time drug transaction took place nearby on the sidewalk. The sheriff noted that he was not in uniform at the time.

Urquhart said that kind of illegal street transaction would no longer occur in Seattle, where the law permits an adult to buy personal amounts of marijuana legally and openly in regulated stores.

“What we have in Washington State is not the wild, wild West,” he said.

The sheriff asked the senators to consider a change in federal law that would permit commercial banks to service legalized marijuana stores. He said money-laundering regulations were forcing the stores to operate as cash-only businesses, raising the risk of armed robberies.