US Steel is now Japanese, btw

Depending on the specific concern, I assume what mostly matters is where the facilities are, not who owns the company. (At least so long as it's an ally.)

it should be irrelevant who owns it. regulations ought to be robust enough anyway. technology export controls, worker protections (OSHA, business continuity, financial integrity, audits), market protection (no abuse of market power, ie. no dumping no Apple/platform/gatekeeper shenanigans, etc.)

Not yet. The federal government could still block it or the acquisition could fall through for other reasons.

It takes (up to) 456.23% import tariffs[0] to achieve that 17%.

So you pay china $1 million for some amount of steel (via vietnam) and then pay the us gov $4.56 million for a total cost of $5.56 million.

It’s amazing that so many steel companies are still underperforming in the USA seemingly in spite the intense protectionism.

0: https://www.latimes.com/business/la-fi-us-vietnam-steel-trad....

So, essentially, we can all become factory workers if we're willing to accept a drastic decrease in our standard of living.

Is the percentage of steel imports relevant, when most of the metal consumer products are coming from abroad?

Simple stuff like pots and pans, cutlery, potato mashers. Then industrial parts. Farm equipment. Eventually, cell phone frames and more sophisticated stuff. I think this is what the parent comment is alluding to.

Ywes, but if we have cheap materials here, it makes it more enticing to manufacture here as well.