WRT cancellation clauses: They are included in these massive defence contracts because these project are so enormous that they take over the entire enterprise. If the contract goes away (and the contractor is not at fault), then the company has to find new customers -- and how many new customers do you think are pounding on the gate at a naval shipyard that specializes in aircraft carriers? When new work is found, then the company has to retool and hire new workers, all while it has no income.

There isn't a qualified bidder in the world that would compete for a major defence contract without cancellation clauses.