Massachusetts is about to do in the Northeast Interstate Dairy Compact.

The compact, which sets minimum milk prices in the Northeast, won’t die immediately, even if the Massachusetts General Court eventually decides to withdraw the Bay State from it.

The death will come next year, when Congress considers whether to renew the enabling legislation that powers this important protection for small dairy farms in Maine, New Hampshire, Vermont, Massachusetts, Connecticut and Rhode Island.

Massachusetts doesn’t have a lot of dairy farmers: about 320 family farms in 1999, according to the state, with about 25,000 dairy cows, according to the U.S. Department of Agriculture. Even Connecticut has more cows. By comparison, Maine has about 42,000 dairy cows; Vermont, 160,000.

What Massachusetts does have are powerful supermarket, wholesaler and other industry lobbies, who see the opportunity to pull the plug on the compact as a way to open up profit margins. But if Massachusetts — and its 12 U.S. representatives and senators — bail out on the compact, its doom is virtually ensured before Congress.

Simply put, the Midwest despises the Northeast Interstate Dairy Compact. Large dairy farmers there want to be able to sell milk here at prices that would put Maine and Vermont farmers out of business.The compact almost didn’t survive the last congressional budget cycle; it took concerted efforts by the Maine and Vermont delegations, as well as a series of events bordering on the miraculous, to save it. If the state at the geographic center of that compact disappears, it won’t be hard for powerful dairy industry concerns in the Midwest and Southwest to unravel the compact before Congress.

While trucking in milk from the huge factory farms of the Midwest might help some businesses, such a development would devastate New England’s dairy industry. Contrary to claims made by the federal Office of Management and Budget in 1998, New England’s dairy farms cannot compete against an influx of new milk supplies; nationwide, there is simply too much milk production, and not enough demand regionally.

As a strict measure of its faithfulness to letting the marketplace choose winners and losers, the milk compact is sour policy. But as a means for promoting economic diversity, food safety and open space, it is important to the region. Though the compact has cost consumers approximately 15 cents per gallon since 1996, it returns to them at least that much value through other means. For instance, by helping to keep local farms in business not only through the price support but also by keeping enough other farmers at work. That means a dairy infrastructure of grain dealers, truck drivers and farm machinery sales people will remain. And that means jobs where they are needed most, in the smallest towns whose residents cannot simply turn to alternative industries. This is not mere nostalgia for the bucolic past, but an immediate dollars and cents issue.

Massachusetts owes its neighbors — and its own few family dairy farmers — this much. While it’s telling that the hardest fighting on Beacon Hill to save the compact has come from Vermonters, perhaps the General Court can be yet convinced that preserving the compact means protecting Massachusetts’ long tradition of being New England’s benefactor.