You are trolling, but I'll still bite.
While living in a cave...
We're talking about the same country who got its ass kicked by vietcongs for at least two decades (while using Napalm). Ass kicked in Afghanistan by people using weapons the CIA gave them back in the late '70s when Brejnev invaded their country and IEDs.
Interestingly, this is is a time honored methodology for fighting against a much stronger force and is exactly how I would fight against the US, NATO, Russia, China, etc. if I were in a small country. Take to the hills, don't expose yourself to pitched battles that you will lose anyway and subject your opponent to death by a thousand paper cuts. Americans themselves successfully used this methodology against the British between 1775 and 1781.
The only real ways to fight against it are to either make yourself more popular among the populace than the resistance force (VERY difficult to do) or go full Ghengis Khan.
but was the only one to use them... Twice... Hiroshima August 6th 1945... Enola Gay...Little Boy...Gun Type 16kT. Nagasaki August 9th 1945... Bockscar...Fat Man...Implosion type 21kT.
Other designs were planned. We're talking about weapon testing... If the war wasn't over back in the old countries, they would *never* have dropped a nuclear weapon in europe.
So..... its the summer of 1945. YOU are Harry Truman. The war has killed, what 50 million people so far. The battle of Okinawa has just finished and it killed.... oh about 200,000 people. (about half being soldiers of the two side and the rest civilians). That was essentially the dress rehearsal for the invasion of Japan itself. You've just been told about these new kinds of bombs. What would you do? Try to finish the war off by using them and then bluffing the Japanese by saying you have a thousand (you don't. you have two) or go ahead with the invasion?