Heinlein would have filled the tank with water. France has the ambition, the launch sites, and the familiarity with radioactive materials. Their commercial launch concerns are partly supported by government funding. Some of the Soviet offshoots might have or might acquire the knowledge and the plutonium. China might buy both from any of them.
China has wealth as well as poverty.
Oil pays for it all. And even the United States might not be entirely shut out.