In joining the US subsidy race, Europe risks ushering in a new era of protectionism.

Joe Biden's clean technology law has dragged the European Union into a subsidy battle that might spark a transatlantic trade war, just as the allies are banding together to counter Russia's invasion of Ukraine. The EU has consistently maintained the global rules-based system, even as the US has grown increasingly antagonistic to the restraints it adopted as a member of the World Trade Organization. However, Biden's $500 billion in ....