Saudi Arabia’s state-owned oil company, Saudi Aramco, is going public next year. The company’s spokespeople believe this public offering will be record breaking, and expect the five percent of the company expected to be on offer will be sold at a price high enough to value the firm at $2 trillion. If that’s true (a big if, according to most outside observers), it would make Saudi Aramco the most valuable publicly traded company on the planet. Unfortunately for Riyadh, weak oil prices aren’t the only thing working against this landmark IPO. As the WSJ reports, a boom in the U.S. petrochemicals industry—one of the offshoots of the shale boom—is blunting Saudi Aramco’s efforts to move down the oil supply chain:

The shale revolution means the U.S. is already much less reliant on Saudi Arabia for its oil needs. Less appreciated is the threat…