ARLINGTON, Va. — For the first time, the Department of Defense has specifically made it a crime for a servicemember to patronize a prostitute. The punishment: up to a year in prison, forfeiture of pay and dishonorable discharge.

The formal order came in a presidential executive order signed without fanfare Oct. 14, directing changes in the Manual for Courts-Martial. It is part of an assault the military has been waging against human trafficking.

A Defense Department spokeswoman, Lt. Col. Ellen Krenke, said in an e-mailed response to questions that “prostitution” and “pandering” will now be among the offenses covered by Article 134 of the courts-martial manual.

Paying for sex used to fall under the “Solicitation of Another to Commit an Offense” listed as part of Article 134, which executes the corresponding section in the Uniform Code of Military Justice, Krenke said.

It prohibits “all disorders and neglects to the prejudice of good order and discipline in the armed forces” and “all conduct of a nature to bring discredit upon the armed forces.”

But the October executive order makes prostitution and pandering specific offenses, she said.

Krenke said that the DOD made the change as part of its effort to combat human trafficking by taking on the sex exploitation industry, as set forth in a December 2002 National Security Presidential Directive that says in part:

“Our policy is based on an abolitionist approach to trafficking in persons, and our efforts must involve a comprehensive attack on such trafficking, which is a modern day of slavery. In this regard, the U.S. Government opposes prostitution and any related activities, including pimping, pandering, or maintaining brothels as contributing to the phenomenon of trafficking in persons.”

The military needs to change its general mind-set that tolerates prostitution, said Sara Mendelson, senior fellow at the Center for Strategic and International Studies in Washington.

Mendelson, author of a report on human trafficking and peacekeeping in the Balkans, said the military needs to get the word out about the change on prostitution to make it effective.

“The issues is not whether activists or experts in Washington, D.C., know about it, it’s whether the soldier in the field understands; it’s whether the commander in the field understands that this is a change from the previous regulation in the Manual for Courts-Martial,” she said.

As early as November 2004, the services began to write online training courses that cover prostitution within the framework of human trafficking, Krenke said.

Krenke said it teaches that “you don’t have to be a professional criminal to contribute to the trafficking industry. You aid and encourage trafficking in persons without engaging in it directly, by hiring a prostitute.”

While the change to the courts-martial manual makes it clearer that prostitution is illegal, Marine commanders from the top down already know that prostitution is a punishable offense and have taken steps to combat it, wrote Marine Corps spokesman Maj. Douglas Powell via e-mail.

“Marines are briefed by their commanders, especially those who are deploying overseas, that they should not engage in prostitution,” Powell said.