A community that has just seen one of its greatest assets — the Minnesota Orchestra — torn apart before its eyes cannot afford a similar tragedy on the Southwest Corridor light-rail project.

The proposed line linking the metro area's most prosperous suburban quarter with downtown Minneapolis, the University of Minnesota and downtown St. Paul would bring enormous environmental, economic and social value to the whole region for generations to come. It's a vital appendage of the regional transportation network and symbolizes decades of hard work in achieving the geographic and cultural unity that the Twin Cities needs in order to compete and prosper. Southwest demonstrates clearly that our metro region is stronger together than apart.

That's the principle that should guide Mayor-elect Betsy Hodges and new members of the Minneapolis City Council as they prepare to take office and confront the region's thorniest problem. Yes, it's true that the city was misled by promises that freight trains would be diverted from the woodsy Kenilworth segment once the light-rail line was built. And, yes, the city is right to feel betrayed if, as now seems likely, legal and technical considerations will keep the freight track in place.

But Minneapolis plays a dangerous game if it drifts toward a conclusion that the Southwest line is no longer in the city's best interest. A long list of long-term benefits to the city should put that notion to rest. By even appearing to flirt with a veto, Minneapolis has incurred a huge perception problem.

Not even an extra $160 million for two shallow tunnels can seem to satisfy the city, or so it's said. The city seems willing to block light-rail service to the southwestern suburbs for the sake of a few upscale Kenilworth complainers, or so it's said. Those perceptions may be untrue, but that doesn't make them any less real and any less of a problem for Minneapolis. There are many avenues to revenge if the city, in the end, rejects Southwest. Already there's talk among suburban and county officials of subverting the city's streetcar plans in retaliation.

For St. Louis Park, the stakes aren't quite so high. Everyone agrees that diverting freight trains atop 20-foot berms was a ludicrous option. But the suburb's leaders look exceedingly petty in rejecting any new freight diversions, as St. Louis Park Mayor Jeff Jacobs appeared to do in a recent letter to Gov. Mark Dayton. After all, there's still a slim chance that a feasible solution can be found, especially if federal mitigation money can be tapped. If St. Louis Park ends up vetoing the Southwest line because of four additional freight trains a day, it will have much to answer for.

At the moment, this issue is too hot for rational decisions, which is why Dayton called a timeout so that cooler heads could take a deep breath and calmly sort out the best way forward. Serious mistakes have been made on all fronts, but they are old news at this point.

Minneapolis pushed for three clarifying investigations now underway. The first makes one last-ditch effort to find a suitable freight detour, this time with a study conducted by a consultant free from conflicts of interest. The second seeks assurances on reforestation in the Kenilworth area. The third insists on certainty that shallow tunnels through Kenilworth would not harm the water quality of nearby lakes, either during or after construction.

Harm to the Chain of Lakes from shallow tunnels is probably the only legitimate reason to stop Southwest. As for complaints and lawsuits from neighbors who don't want to live near trains (even for 20 seconds at a time), well, those are inevitable parts of any major transit project. The larger, wider benefit overwhelms those objections.

Kenilworth neighbors have known for 30 years that light-rail trains were likely to run through the corridor. Hennepin County bought the Kenilworth explicitly for future transit development in 1984.

The wider point for Hodges and the City Council is not to be distracted by loud voices or parochial interests, but to consider coolly and carefully the overall value of the Southwest project — both for the city and the region, both now and in the future. Truth is, the city is the Southwest line's biggest winner. Cities are always smart to encourage easy connections to their downtowns from their region's most prosperous districts. It's good for commerce, good for the arts and good for the overall health of the city.

Specifically, Southwest improves Minneapolis' chances for the downtown residential growth it — and its taxpayers — need so badly. Thousands of young workers want to live in the North Loop and connect via transit to jobs in the southwestern suburbs. Most notably, the line opens up major residential/commercial opportunities along the 1.5-mile stretch from Target Field to Bryn Mawr Meadows. Developing that largely industrial wasteland could add significantly to the city's tax base. Southwest also provides the city's hard-pressed North Side residents with easy and affordable access to suburban jobs.

Southwest also strengthens the precarious regional effort on transit. It would be ironic, indeed, after overcoming decades of stiff Republican opposition at the Capitol, that Democrats would be the ones to knock light rail off its tracks. Failure on Southwest would be a profound embarrassment for Dayton and the DFL's legislative leaders.

In the coming months, Minneapolis' new leaders may have to make a huge municipal-consent decision for the whole region. Shallow tunnels, if they pose no danger to the lakes, represent an extraordinary mitigation for Minneapolis. They more than compensate for the broken promise on freight trains. The city should take great care not to let this game-changing opportunity pass by.