It’s not exactly a civil war, but the disagreement between the Midwest and the Northeast over which is responsible for the dirty air in this region has both a way of life and regional identity at stake. It also is a good example of why Maine was right to join regional air-pollution coalitions and support laws that keep the state in federal compliance.

Maine has operated for several years under the idea that it can better meet Clean Air Act requirements by agreeing with other states in the region to goals and timetables than by trying to work alone. The need for cooperation is evident because prevailing winds mean more to air pollution than do state borders. Not incidentally, by working together the coalitions give each state more clout in Washington than it would have on its own. Maine has worked in organizations made up of states along the Eastern Seaboard, another that includes the Northeast and Midwest and an eight-state group composed of New England and New York.

It is this last group that has the Midwest so unhappy and prompted angry press releases last week from a trade group there. Led by Maine, the group has told the Environmental Protection Agency that the region’s air would be cleaner if the EPA would apply the same pollution controls to the Midwest’s coal-fired electric utilities that it applies to the rest of the country. The old plants were exempted under the original Clean Air Act and provide cheap electricity to their customers and dirty air to as many places as the wind will carry it.

Gov. Angus King and Ned Sullivan, commissioner of the Department of Environmental Protection, have urged other Northeastern states to tell the EPA to require the new standards for the Midwest. Not surprisingly, Midwest Ozone Group, which represents 30 utilities in 10 states in that region, thinks the plants should be allowed to keep their exemptions and are challenging the Northeast group by denying that this region suffers from dirty air from the old plants. The obvious state to pick on is Maine.

Obvious because Maine has been a leader in urging its neighbors to rally round and because it is farthest from the Midwest and so, wind patterns aside, potentially least affected by MOG’s ozone. Maine’s position is that most of its air pollution comes from nearby states, it produces a significant amount itself and some — perhaps enough to push parts of the state into noncompliance — comes from the Midwest.

Parsing the pollution is the EPA’s job; the fact remains that Maine’s political leaders, having joined the Northeast coalition, are defending the coalition’s case by pointing to the pollution in the Midwest. The appeal of cleaning up the entire region’s air by forcing another region to improve its technology is clear. And even if Maine receives only a small portion of that benefit, it is still in this state’s interest to pursue this because it allows Maine to negotiate pollution improvements with neighboring states. Sort of a back-scratching deal.

MOG has gotten particularly active recently because the Northeast coalition is proving to be effective. Maine should stay with it. All the states in this region will benefit if they continue to work together.