The other Nato members are mostly honourable, but I still wouldn't book a vacation in Narva.

This hints at exactly what one of the problems is. They may be honorable, but they're mostly useless. They've depended on the USA to spend all the money, and to wield all the sticks, for decades. Meanwhile the USA went deeper and deeper into debt (partially because of being the world's policeman, and partially for various other reasons), and we simply can't do it anymore. We are nearly in a debt spiral (some folks say we already are in one, but I still have a modicum of hope that we can get out) and need to do *something*. Not necessarily what we are doing, of course, but something. Business as usual just can't happen or we will decline into oblivion (that is likely to happen anyway, but we can at least try to forestall it somewhat).