House Armed Services Committee Chairman Les Aspin (D-Wis.) last night called on the Democratic Party to shed its image as the "Doctor No of the defense debate" and stand for such programs as reform of weapons procurement, strengthening U.S. conventional forces and streamlining the military chain of command.

In a speech prepared for delivery to the Henry M. Jackson dinner of the Coalition for a Democratic Majority, Aspin said Democrats must erase the perception of their being "soft on defense" if they hope to regain national leadership.

"If Democrats want to spend the rest of their careers writing op-ed pieces and giving lectures at universities, then we continue to stroke our anti-defense image," he said. "But if we want to make defense policy in the White House and Pentagon, then we had better stand for something.

"The voters are not attracted to national security naysayers."

Aspin, an influential Democrat on defense issues, acknowledged the party's "painful soul-searching." The speech marks Aspin's first public effort to set out a Democratic defense agenda since taking over in January as chairman of the Armed Services Committee.

Democrats long have been attacked by the political right as being weak on defense issues, he said. What is especially "harmful" today is that the same opinion is held by moderate voters, he said.

Aspin described this perception as a "bad rap" that emerged because the defense debate has focused on military rearmament, and "on specific weapons Democrats have stood for negatives. Democrats have been cast consistently in the role of chief anti-. Anti-B1 [bomber]. Anti-neutron bomb. Anti-MX [missile]. Anti-Strategic Defense Initiative. And, thus, in the public mind: anti-defense."

"The point is that we don't seem to stand for anything anymore," Aspin said. "In the debate that goes on daily in the newspapers and on the television screens, Democrats are not shown being for anything in the defense area. We are always against. We are the Doctor No of the defense debate."

He urged the party to reshape its image, to "stand for defense without nonsense." To accomplish this, he said Democrats should propose practical alternatives to weapons they oppose.

On defense spending, he suggested that Democrats should not only look for cuts, but also should add "a few billions back" to programs ignored by the Reagan administration, such as weapons necessary to fight a conventional war.

Democrats also should take the lead on cleaning out "the Augean stable of Pentagon procurement," he said, an issue that the Reagan administration has allowed to "get away from it politically. Democrats, therefore, have an opportunity to confront a core defense issue in a creative and rational way. This is a real Democratic opportunity."

Another ripe area for reform cited by Aspin is interservice rivalry, which, he said, results in the Joint Chiefs of Staff "essentially bolting together the individual service policies."