First, you could say something similar about many restrictions.

If there is one steel monopoly and you ban being a monopoly then we can apply the same logic you have there.

To be completely fair, the “illegal part” of being a monopoly is not generally in the existence of the monopoly itself, but in the monopolistic actions the company may take. However, those actions may be a fundamental part of the function of the company, and I’d argue that country of ownership is another property that should be eligible for restriction.

Second, and _far_ more importantly, it is not clear to me that it’s unconstitutional to make a law that a foreign company can’t operate a certain type of business in America.