Recently, the idea to use the nuclear fusion for obtaining clean, safe, and inexhaustible energy and, thereby, for solving also the climate crisis, is attracting policy makers and citizens. In the present contribution, the ways to perform the fusion of deuterium and tritium (magnetic and inertial confinement) are briefly described. Then the many problems that still need to be overcome are presented and discussed. As demonstrated by the scientific reports, the nuclear fusion will fail to produce exploitable energy in a near future.