Why can you not make a hydrogen bomb?

Answer 1

Scientists have long tried to make a pure Hydrogen weapon, the problem with all the designs that have been attempted is the compression of the Hydrogen material to its flash point. Hydrogen can be compressed under great pressure to make a functioning weapon; however, the only way we have managed to do this practically is through the Teller-Ulam design. This design uses a nuclear fission weapon to compress the Hydrogen within a secondary device to start a fusion reaction.

Without the ability to use a fission weapon to ignite the Hydrogen, we do not have a way to compress it to its flash point. There are still design attempts that have been circulated to make a pure fusion Hydrogen weapon, but none have been tested and the problem of getting Hydrogen to flash is always the founding problem. Most designs have been abandoned, and there are currently no known developmental plans by the United States to Pursue this design.