I was just reading about candy bars for a trivia night, and the internet tells me the UK Milky Way is the same as the US 3 Musketeers bar. As in, it omits the caramel.
Also, the 3 Musketeers candy bars used to come with 3 flavors in the package: chocolate, strawberry, and vanilla. Cost cutting led to eliminating the 2 less popular flavors.
It's super similar though. But without the caramel and the soft stuff is vanilla flavoured instead of chocolate. I like them better actually. The mars bar is too chocolatey for me (while actually having really bad quality chocolate)