Iran is studying building a nuclear fusion reactor, which no other country has managed to create. Iran already has a highly controversial nuclear fission program, which Western nations allege is aimed at building nuclear weapons. So far, nuclear fusion has never been used to create energy for civilian use—it’s only been used to make weapons, causing the thermonuclear explosions of the H-bomb. The head of Tehran’s nuclear energy program said the country was putting $8 million into “serious” research on nuclear fusion, which is expected to last two years. It would take another decade to build a reactor. A group of nations—the U.S. the European Union, China, India, Russia, Japan, and South Korea—agreed in 2006 to put resources together to fund a $12.8 billion nuclear fusion reactor on Cadarache, France. The international effort is necessary, members of the agreement say, because nuclear fusion is mind-blowingly expensive, and so partnership is the only way to advance the science. Iran says it would be happy to join an international fusion effort but would work on the project alone if it wasn’t invited.