Where is the flux capacitor?
No, actually I don't realize that. Wikipedia, like the good leftist tools they are, splits hairs to say their are only "backpack nukes". OK. We don't see the device being carried in a suitcase, we are told it is a 1 Megaton bomb, I believe (which lines up with the details on our smallest weapon outlined below).
Net-net: do suitcase nukes exist? Yes, at least close enough for me. And for the jihadi wack-jobs who want one so badly.
From Wikipedia entry for "suitcase nuke" Only a nation with an extremely advanced nuclear program could manufacture warheads small enough to fit into a suitcase. Both the USA and the USSR manufactured nuclear weapons small enough to fit into large backpacks during the Cold War, but neither have ever made public the existence or development of weapons small enough to fit into a suitcase.
The smallest nuclear warhead manufactured by the USA was the W54, used for the Davy Crockett warhead which could be fired from a 120 mm recoilless rifle, and a backpack version called the Mk-54 SADM (Small Atomic Demolition Munition). While this warhead, with a weight of only 51 lb (23 kg), could potentially fit into a large suitcase, it would be a very tight fit.
While the explosive power of the W54 up to an equivalent of 1 kiloton of TNT is not much by the normal standards of a nuclear weapon (the bombs dropped on Hiroshima and Nagasaki at the end of World War II were around 13 to 15 kilotons each), it could still do tremendous physical damage to a structure (it would be many, many times more powerful than the explosive attack on the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma in 1995, for example, with a yield of 0.002 kiloton).