... by making a promise that he couldn't keep, to keep the airline going, apparently unconditionally.
So the "intransigent" unions basically sat there thinking to themselves, "We can hold out as long as we like, because Berlusconi won't let it fail."
They were wrong. Berlusconi has no choice. Had he acknowledged that in his election campaign, the unions might have been more realistic about what of Alitalia could survive, and accepted a workable deal.