Legal battles have been joined between Fort Worth and two groups of valued employees, police and firefighters.It’s a sad but apparently necessary step in ironing out terms of employment for these crucial public safety personnel. The dominant issue in both cases is pension benefits and how to pay for them.Out of necessity, the City Council has taken a firm stand on measures to reduce its unfunded pension liabilities, which as of a year ago amounted to more than $1 billion.The Star-Telegram Editorial Board has strongly supported the council’s decisions on addressing the strength of city employees’ pensions, and that support continues as the police and firefighter litigation moves forward.The unfunded liabilities must be addressed, and better methods than those adopted by the council have not been put forward.The Fort Worth Professional Firefighters Association filed a lawsuit Wednesday objecting to the city’s final contract proposal.Fort Worth firefighters have a collective bargaining contract; other city employees do not. The city follows a “meet and confer” process on employment terms for police, not a formal collective bargaining contract. The president and former president of the Fort Worth Police Officers Association filed suit in November 2012.The crux of the disagreement, which the city has declined to submit to mediation or arbitration, is a plan to reduce the multiplier used in calculating pensions and to increase the number of years of highest salary on which pension payments are based. The city also intends to remove overtime pay from pension calculations.The firefighters association has proposed that firefighters be allowed to break away from the pension fund serving other city employees and to increase individual payments into a new fund, keeping it stable.Rightly, the City Council has seen that proposal as unacceptable and said it would leave the city vulnerable to a lawsuit from other city employees whose pension fund would be further weakened.Firefighters association President Jim Tate called the city’s position “a disingenuous ‘take it or leave it’ contract.”That’s harsh. Another way to put it is that the city put forth a tough and non-conciliatory offer and firefighters failed to come up with a workable counter-offer.