NEW YORK -- From their modest home in Hampton, Conn., husband-and-wife entrepreneurs Kate Donnelly and Clay Colt have outfitted America's peace activists with buttons, T-shirts, bumper stickers and other political paraphernalia for the last 12 years.

As mail-order magnates of the American left, Donnelly and Colt have documentary evidence of the shifts underway in the large but amorphous constituency known as the peace movement.

"As the headlines change, our business changes," said Donnelly. In the last year, demand for buttons such as "Stop the Cruise Missile" and "US/USSR Disarm" has "bitten the dust," she said. But business has become brisk for "Homes Not Bombs," "Reproductive Rights For All Women" and "Protect Our Earth," illustrated with NASA's ubiquitous photograph of the planet from afar.

Across the country, dozens of organizations once devoted to preventing nuclear war are struggling to redefine their approaches and reinvigorate their flagging memberships. Faced with the thawing of the Cold War, their members are defecting to groups that deal with issues such as homelessness, abortion rights and the environment.

A few groups, especially those focused on defeating particular weapon systems, have folded. Others face shrinking budgets and staff cutbacks as fund-raising grows more difficult.

But most peace and disarmament groups persevere, many taking up the cry for "conversion" -- reducing the military budget and redirecting the spending to social needs. However, they are discovering that it is harder to mobilize people now than when fears of nuclear war were running high.

"When the situation is outrageous, you can count on people to get out there and demand change," said Cora Weiss, a longtime activist and international representative of SANE-Freeze, the nation's largest disarmament group. "If the situation is not outrageous, they do their laundry."

Many peace activists say that, with Presidents Bush and Mikhail Gorbachev meeting at a summit, the main force that motivated the peace movement's marches on Washington and petitions to Congress has disappeared.

"The fear factor is gone," said David McReynolds, a longtime staff member of the War Resisters League. "Gorbachev, ironically, has eliminated the fear factor."

"Before, we had an administration that was thinking the unthinkable about nuclear war, and people were scared," said Peter Drucker, program coordinator of National Mobilization for Survival, a New-York based group that five years ago had 200 affiliates around the country and now has 80. "Now people are nowhere near as scared, but they are worried about our own society, which seems to be coming apart at the seams."

Groups such as the Coalition for a New Foreign and Military Policy, the political action committee Freeze Voter, Space Watch and the Committee to Save the ABM Treaty have closed in the last two years. In order to survive the 1990s, other groups are increasingly shifting their activities to domestic concerns and forming new alliances on national and local levels.

In Washington, representatives of traditionally single-focus disarmament groups are meeting with organizers working on such diverse issues as toxic waste, housing, health care, AIDS and homelessness to form a national coalition pushing to halve the military budget and spend the savings on social services.

Members of Maryland United for Peace and Justice, a coalition of 70 groups, are planning a commission to recommend ways to begin converting the state's military industries into non-military enterprises. In a recent survey, the coalition's members ranked economic conversion, pollution and poverty as their top priorities. Disarmament, which ranked in the top two in previous years, was seventh.

Peace and disarmament groups nationwide sent more than 20,000 activists to the "Housing Now!" march on Washington last October, where they gathered at the Pentagon and carried signs reading, "Housing Not Bombs."

In Westchester County, N.Y., 120 people attended a potluck dinner sponsored by the local SANE-Freeze chapter to hear an environmental expert discuss his trip to the Soviet Union, where he met with Soviet scientists and environmentalists. The talk prompted the group's concern about pollution in areas such as Long Island Sound.

"Someone said if the nuclear bomb won't kill you, the pollution will," said Judy Lerner, chair of Westchester County SANE-Freeze. "That seems to be filtering through to us."

But all of the casting about for new angles has led to criticism of the peace movement for apparent lack of direction. McReynolds, 60, a self-described "old leftist" and a member of the Socialist Party, characterized the current peace movement as "confused . . . largely because it's a white, middle-class movement."

"For example, the rest of the country has forgotten about civil rights, but if you're black, you can't ignore it," he said. "The peace movement is made up of people who are able to shift their agendas. They are good people, but they shift to whatever is popular, like the environment. They're forgetting that we are still in a world able to annihilate itself in 15 minutes."

Several groups have reminded constituents that the Cold War is far from finished, that nuclear war remains possible and that Bush proposed increased military spending for fiscal 1991.

"We are being hoodwinked. Bamboozled. Scammed," began a recent fund-raising letter from Benjamin Spock for the National Mobilization for Survival. "And if we do not act now, George Bush will cheat us out of our Peace Dividend."

But with the "fear factor" diminished, organizations are finding it harder than ever to raise money from foundations and private contributors. "Reducing the military budget just doesn't have that impact as a gut issue," said John Tierman, editor of Nuclear Times, which lost a three-year grant from the MacArthur Foundation and has cut back from bimonthly to quarterly.

One group's disarmament campaign was rejected by a foundation previously an enthusiastic supporter of such work, according to the group's director, who asked not to be identified. "We got a response saying, 'Sorry, we're not funding peace anymore, just the environment,' " the director said.

Mal Warwick, whose company has raised millions of dollars for advocacy and left-wing groups through direct-mail and telephone fund-raising campaigns, said that, six or seven years ago, most of his clients were peace and disarmament organizations. Now, he has no such clients.

"Their priorities are not attractive enough for a large enough proportion of the public for them to make a go of it by mail," Warwick said.

However, there is plenty of money to be raised for what Warwick calls the current "hot-button issues," such as environmental protection, access to abortion and animal rights.

These are the same trends that Donnelly and Colt see in their button business, although one slogan has never lost its popularity. " 'Question Authority' is always a big one, always," Donnelly said.