This is another interesting part. How can the US "force" a sophisticated wealthy sovereign nation that culturally and morally values banking privacy (not only for the profits), like Switzerland?
It cannot be understated how much power, control and ownership the US has of the world financial system. If Switzerland did not comply, they would have been fully cut-off, unable to participate in any finance at all. It happened swiftly (no pun intended [1]), there was no discussion, only power.
Most of the west is mostly aligned with what the US is doing, so it's not a big deal. Every government wants more visibility, control and power over finances. It is akin to how the US military handles matters of physical force on behalf of the rest of the west.
Just a quick note that the US is equally powerful in the financial arena as they are militaristically, if not more so.
[1] SWIFT is one of the systems Switzerland could have been cut off from