If Cliffs is split up, in the next economic downturn, the US assets will be sold to Mittal for 5 cents on the dollar. They will wait for Cliffs to get weak, because they are the only buyer of the US assets. No one else is going to take them. The fact is, the only way to get long-term shareholder value is to keep the company together. Keep in mind that all the iron ore business is linked and, no matter what you think, EVERY part of Cliffs is exposed to China.
I like complex tax structures for low cost oil companies, but I think Cliffs is a high-cost, marginal iron ore producer and if you wrap it in new clothing, it still will be that, but it will be much easier to destroy.