The Society of Professional Engineering Employees in Aerospace (SPEEA), the union representing 22,950 Boeing engineers and technical workers, will be mailing out strike authorization ballots next week with a recommendation to reject the aerospace giant's latest "final" contract offer. Members will have until February 19 to vote.

The two sides are at odds over Boeing's insistence on dropping pension benefits for new hires. SPEAA argues that Boeing's proposal to replace the existing defined pension plan with a 401K not only represents a 40 percent benefit reduction for new hires, it also threatens the retirement benefits of current employees and retirees. The union estimates that with a large proportion of its members expected to retire over the next decade, the tipping point at which the majority of active SPEEA members are without pension benefits could come within two contract negotiation cycles:

Once this group with the lesser benefit attains majority status in the union, it is expected that Boeing will insert the freezing of existing pensions into its last-best-final contract offers.

That's not an unreasonable concern. This divide and conquer strategy is exactly what other companies have used to roll back pension benefits elsewhere.

With Boeing in the midst of a major crisis over battery fires that have indefinitely grounded the 787 fleet, you'd think they'd want to keep their engineers from going on strike. But apparently not. SPEA has already offered to extend its existing contract. Boeing rejected that offer.

So if this really is Boeing's "last best final contract offer," it's hard to see how the company avoids a long and costly strike.