But the project’s cost increases have come with questionable pay-off. Other DoD projects on the way suffer from their own issues in kind. But weapons experts fear the additional nuclear weapons proliferation SLCM-N would bring might frustrate diplomatic efforts with adversaries. Indeed, conventional strike weapons are more likely to be needed than nuclear weapons in the event of combat; SLCM-s replacing them on some submarines could therefore negatively affect mission readiness. Even as the project’s plans remain nebulous , the DoD says Golden Dome could cost $175 billion — other estimates suggest it could cost trillions .