That seems to stretch the argument pretty far - maybe if we just want to keep vaguely military folk in the country then we could employ them building military grade roads to replace the aging infrastructure. If the project they're actually working on isn't supposed to bear any real fruit then maybe just redirect them to something that isn't a complete waste of resources.

Also, I disagree, I don't think anyone in that realm of government would knowingly sink that much money into a project they intended to fail - they might be overly optimistic about the success, they might be trying to funnel money into their retirement but it takes clout to secure a budget like that and people had to work hard to secure it initially and keep it going - so a failure is probably going to fall under one of these categories - un-achievable, poorly managed, or wholly corrupt.