All pension plans depend on new hire participation to remain solvent. Unlike GM, honest plans are independently administered, and benefits are determined with ongoing actuarial projections.
GM's in-house plan was heavily over-promised by executives as a ploy to keep up production, avoid strikes, hit their bonus numbers, and hit the door running, independently wealthy.
Union members like going on strike even less than their managerial counterparts, and generally avoid it unless they think they're getting screwed. Boeing's proposal wrt the pension plan is rightfully regarded as getting screwed, plain and simple.
Replacement workers? Good luck with that. Hiring machinists isn't like hiring keyboard jockeys or pencil pushers- it takes skill, training and experience to deliver a quality product in that realm, particularly wrt anything as safety-sensitive as aircraft parts...
Boeing knows that a helluva lot better than what are apparently teenage ravers on this forum, guys who've not lived in the real world with real employers, raised real families, paid real bills. Boeing execs are just playing it tough, using fear tactics in a poor economy in an attempt to maximize their own take.
Union workers aren't competitive? hogwash. Ford seems to be doing fine, and the only way that the Japanese makers avoid unionization is with comparable pay and benefits in relation to union employers. On an international level, Germany is still the world's leading exporter, primarily in heavy manufacturing- they're almost universally unionized, with better benefits and only slightly lower pay than their american counterparts...