Most rich, democratic nations, including almost all of the European Union, Japan, South Korea, and Canada provide “just cause” protections for their workers. (Many less wealthy, but still democratic nations eschew employment-at-will, including many Latin American nations and South Africa.) The laws vary, but they generally provide what only a union contract in the United States does: You can’t be fired for any old reason. Many nations even have an independent labor court system to adjudicate such cases. America’s much vaunted Constitution is not so generous.
Surely the best way to close our achievement gap against these countries is to allow our teachers to be fired without cause.