The evidence needed for Maine’s congressional delegation to make the case to save Brunswick Naval Air Station is in a letter sent from the Navy to Sen. Susan Collins this week. The Base Realignment and Closure Commission, which recently downgraded Brunswick from realignment to closure on its list, should see the letter as a specific endorsement of the crucial role for the base and vote against closing or realigning it.

The Department of Defense will go only so far as to say Brunswick should be realigned – reduced from an air station to an airfield devoid of its own planes but highly important to the service nonetheless. The letter from Anne Rathmell Davis, special assistant to the secretary of the Navy for base realignment and closure, described why the base was not expendable.

“The loss of [Naval Air Station] Brunswick will increase P-3 response time to any maritime threat against the northeast coast of the United States,” the letter reads. “Because this area is not a standard operating area for U.S. Naval vessels, and because of the proximity of NAS Brunswick to the great circle navigation routes from Europe, P-3s operating out of NAS Brunswick currently provide [Marine Homeland Defense] initial response coverage.” Later, it says, “Numerous sites in the northeast have been considered as potentially feasible locations to conduct P-3 detachment operations … and NAS Brunswick continues to be viewed by the Navy as the optimal site in New England for P-3 detachment operations.”

The letter details the many ways the Navy and the military generally need Brunswick. It is a crucial refueling hub; it is crucial for military aircraft coming from Europe and for NATO joint training exercises. It serves as a training facility for DoD aircraft and Air National Guard. Its location allows armed aircraft to depart on maritime missions without flying over inhabited areas.

For all of that, however, DoD still would take the planes from Brunswick under realignment while leaving the airfield intact. Clearly, the BRAC commission doesn’t like that idea – if it did, it would not have moved Brunswick from realignment to consideration for closure. The hope for Brunswick is that the commission’s dislike for realignment and the Navy’s insistence that it needs the facility combine to keep the base open.

The letter spells out a clear role for P-3 surveillance aircraft and for additional uses of the Brunswick base beyond the Navy requirements. It is hard to believe that the required seven of nine commissioners could ignore these attributes and vote to close the base.

The DoD debated internally almost until the May 13 closure announcements whether to list Brunswick for closure. But no one knows better than the Fleet Forces Command that the Atlantic is better served by having Brunswick remain open and operational. Realignment is an inadequate option in part because it ignores the effect on the local community. Keeping Brunswick open fulfills the demands described forcefully by the Navy.