I haven't met a single chick that enjoys knives like any red-blooded american male does. Why? It's loving sketchy to pull out a knife just to show someone, they realize this.
I hate that, so I make my best effort to buy U.S. Steel.
Depends on who makes it, frankly I avoid butterfly knives altogether. I prefer Columbia River, Gerber, Kershaw, Spyderco, Benchmade, etc. Those can have foreign steel but the craftsmanship is generally along the higher end.
Anything with moving action gears or springs, or a safety lock is generally made in the US. (usually only show up on higher end knife maker's inventories)