Rep. Joseph P. Addabbo (D-N.Y.), chairman of the House Defense Appropriations subcommittee, said yesterday that he will press for a cut in planned Pentagon spending of $7 billion to $9 billion in fiscal 1982 rather than the "minimal" $2 billion reduction proposed by President Reagan.

"They spend that much on paper clips," Addabbo scoffed in dismissing the $2 billion figure as much too low. He conceded, however, that it is "doubtful" the subcommittee will vote with him this year although it might well do so in 1982.

"The mood is definitely changing," Addabbo said after sounding out members on how much money should be budgeted for defense, considering strains on the economy.

"They're starting to ask questions like: Do we really need the MX and the B1? You didn't hear this a month ago," Addabbo said of House members. "They're becoming more skeptical."

Documented cases of Pentagon waste and a backlash by constituents stemming from deep cuts in domestic programs are turning the tide, Addabbo said. The Pentagon is even more vulnerable on its money requests for fiscal 1983 through 1986 than on fiscal 1982 alone, he said.

"They don't even know what they want to spend all that money on yet for the next four years," Addabbo said of Reagan's five-year plan for rearming America in fiscal 1982 through 1986.

"All they have sent us is the total amounts of money the generals and admirals want, not the items on which it would be spent. I'm not moving on my bill till they tell me what's in their five-year plan," Addabbo said.

He said it would be mid-October before his defense subcommittee, the most influential House unit in deciding defense appropriations, would vote on the Pentagon's fiscal 1982 money bill.

A veteran subcommittee staffer said he could not recall an administration that has taken so much time to detail its five-year defense plan. Hearing this, Addabbo quipped: "That's because they leave this to the undersecretaries, and they don't have any undersecretaries."

Although Addabbo overstated the case, the administration has taken months to fill two civilian management slots at the Defense Department.

Asked how he would reduce fiscal 1982 spending by $7 billion to $9 billion, Addabbo said his staff is compiling a detailed "hit list" that would delete money for deploying the MX land missile, deny funds for the updated B1 bomber and postpone funding for theater nuclear weapons.

"Theater nuclear weapons are undeployable," Addabbo said, referring to growing opposition to them in western Europe where the Pentagon would like to deploy them. Opposition to the nuclear-tipped missiles is particularly strident in West Germany.

Addabbo claimed that the $13 billion Reagan intends to cut from the Pentagon's spending account--$2 billion in fiscal 1982, $5 billion in fiscal 1983 and $6 billion in fiscal 1984--is "not a true cut but a symbolic one. It was supposed to be symbolic to other Cabinet members and to the general public."

Addabbo asserted that Reagan is trying to convince other Cabinet members, whose domestic programs will be cut severely, and the general public, which soon will feel the impact, that the Pentagon is sharing in the president's austerity program.

Alabama's Jack Edwards, the subcommittee's ranking Republican, disagreed with Addabbo. Acknowledging that Reagan's cut signaled that the military could work with less money, Edwards said: "I don't feel there has been any opening of the door" to further defense cuts.