The contracts we have signed in the past have limited our actions in the present. We all like to believe we can influence events by acting in unison, but the reality is that Brown and Purple move when they are forced to by concerns that lie outside the Unions.
That said, there is a lot wrong with ignoring your employees for 3-5 years while you reap the benefits of clever negotiating on your part and poor reading on the employee's part.
It would seem that a fair and timely handling of contract negotiations would send a strong message of cooperation and improve willingness to work together. However the exact opposite message has been sent over and over without any attempt to hide or repair the damage.