A version of this post appears in today’s New York Times Room for Debate forum, “Must Teachers and School Officials Be Foes?“

It’s rarely wise for administrators (or school boards, or mayors) to pick unnecessary fights, but it’s also unwise to shy away from those that need to be fought through on behalf of the public interest.

School systems like Chicago’s face many opportunities for collaboration with teachers unions. For example, preparing to teach to the new, higher “Common Core” standards is an effort best done together, with the expertise of front-line teachers playing a key role.

But there are other times when the interests of the teachers and those of the broader public are not the same. Especially when money is tight, administrators (and elected officials like Rahm Emmanuel) have a duty to look out for the public fisc. More cash for teacher salaries, as the Chicago Teachers Union is demanding, means less for everything else—after-school programs, early childhood initiatives, police, public health, everything. Leaders need to hold the line.

Likewise with the issue of job security. Unions are built to protect their members’ jobs and pensions, regardless of performance. The public, on the other hand, is best served when administrators put the most effective teachers in the classroom, and ask the least effective to find other lines of work. In a system like Chicago’s, where declining enrollment and excess capacity is going to force leaders to close dozens of schools, these closely held values—call them fairness versus meritocracy—are in direct conflict with one another. Happy talk about “collaboration” won’t sugarcoat that fact.

Conflict is unavoidable—at least if we want our politicians, school boards, and administrators to do the job that we must trust them to do on behalf of children, taxpayers, and the nation’s future.

-Mike Petrilli