In federal court here yesterday, Javed Nawaz spoke firmly as he declared, "My parents never raised me up to be criminal . . . . I am really a victim of circumstances."

His lawyer, Allan Palmer, called the 30-year-old Pakistani a "minnow" caught in the government's net. He said Nawaz came from Chicago to pick up heroin in a Washington hotel room because of a sense of obligation to a friend.

But U.S. District Court Judge Stanley S. Harris described Nawaz as "one link in the chain of major international narcotics traffic." The judge sentenced him to 18 years in prison on narcotics trafficking charges in connection with a scheme to smuggle $20 million worth of heroin from Pakistan into the United States.

It was one of the stiffest sentences ever handed down in a narcotics case in Washington, prosecutors said, and involved one of the largest amounts of drugs, though the heroin itself was seized in Pakistan. Nawaz was arrested at the L'Enfant Plaza Hotel in March in an elaborate, videotaped "sting."

At a four-day trial in June, Nawaz, an illegal alien who owns a chain of sandwich shops around Chicago, was convicted of attempted possession of more than 100 grams of heroin with intent to distribute it, traveling across state lines in aid of unlawful activity, and two counts of engaging in telephone conversations in connection with the scheme.

He was arrested in the hotel March 27 after carefully placing five one-kilogram packages of white powder in a suitcase.

Nawaz acknowledged that when he received the packages from another Pakistani he thought they were heroin, but he said he didn't refuse them because, "I was scared for my life."

Actually, prosecution witnesses said, the packages contained flour and sugar that had been substituted for heroin by the Drug Enforcement Administration.

The key government witness was Moazzam Khan, a Pakistani prosecutor and leader of an anti-drug organization, who said he learned in January that smugglers were looking for someone to carry the heroin to the United States. He said he obtained the narcotics from a "subsource," turned them over to American DEA agents in Pakistan, and then flew to Washington himself to pose as the courier.

In tape-recorded phone calls, Nawaz used code words that Khan said identified him as the one to whom the drugs were to be delivered. Nawaz also provided the serial numbers on a Pakistani 10 rupee note. Khan said he had been given half of the bill by the source of the heroin in Pakistan.

On the witness stand, Nawaz confirmed Khan's testimony, but said he had been given the words and the numbers by a friend whom authorities have been unable to locate.

Nawaz said another friend traveled with him on what was supposed to be a one-day round-trip from Chicago and had provided a suitcase. That friend, Sayed Iqbal, also of Calumet City, Ill., was arrested in the hotel lobby, but the charges were later dropped.

"[Nawaz] was asked to do a favor. It was a stupid thing to do," Palmer said yesterday. "But his culpability in the scheme of things wasn't very great."

But Assistant U.S. Attorney Robert E. McDaniel said the drugs Nawaz intended to carry would have caused "a lot of suffering by drug addicts and by those who fall prey to them. It was almost pure heroin that would get divided up into a large amount of very serious crime."

Under federal guidelines, Nawaz will not be eligible for parole for at least six years. Harris warned that "if anything happens to Khan or the subsource, I will do everything I can to keep you incarcerated."