Afnug you are spot on. Been riding a USA made alu Cannondale for 23 years and it is the BEST frame ever, just a beautiful piece of design and engineering.
Aluminum welded in the USA is top notch, you simply will not get
shown any favors during tig welding training, they are extreemely
strict, I am a / used to be a welder, and I have seen how a blind eye
can be turned and someone who is not up to par can get through,
this won't happen in the USA, they are all in unions, they take great
pride in their work, there is a huge market place for such welders
as aluminum is used in boats planes and just about everything else,
China, Taiwan, and many other places will take you on if you look the
part, its easy to make weld look passable on the top, but thats not
good enough, it has to be solid right from the first pass at the bottom
of the bead, and it oxidizes during welding, if proper equipment and
practice is not used from start to finish, if I was really depending on
an tig welded product, I would be happy if it came from Cannondale.